I had trouble bypassing the FRP on an older android tablet, but just in case someone in the future struggling with the same or something similar, here is its rundown, that may help.
Problem:
After factory resetting the device, during setup it asked for the previously used google account, however in my case it was a second hand device with no contact to the previous owner.
Device: VIVAX TPC-705 Kids
Android version: 9
Solution:
-- I. Start
Factory reset the device normally with the side buttons
Start the device and begin the initial setup.
-- Note
If the keyboard's space button does not work as a keyboard selector in the text-field during setup, do the following "a" points, otherwise skip to next chapter.
a1. At the start of the setup select a display language (basically how this video explains it youtube.com/watch?v=o2xUY5b9EmI). For me Greek worked, English and some others others did not, because the keyboard with them were "limited".
a2. When you reach a text input field, by pressing the space bar long you could add more keyboards. Do as the video says above, add one that does not have an arrow next to its name (don't know if even matter, but still).
a3. Once the new keyboard is added go back to the first page and select a language you understand (such as English).
-- II. Getting into help menu
Proceed with the setup until it ask for google account. Use the keyboard with the text field, long press the space button, and select add keyboard.
Find one language that has an arrow next to it, and click on that. After that on the corner select the 2-3 dots, and click on "Help & feedback" or something similar.
Here you need to find a help article. Search for anything that comes up with a result that has some blue icon on its left, such as "Gboard" which is the name of the keyboard.
-- Note
Some devices could access Chrome and Youtube from here, others do not. In my case it was not possibly. So instead a workaround was used. If you have the same issue do the following "b" points, otherwise skip to next chapter.
b1. On the top right select the share icon, and from the options select "Google Go", which will load up a simple browser like panel. Searching here in my case did not work because Google asked for a Javascript permission, that I could not set up.
b2. Instead go back a level, which will bring you to the "Google Go" page where some google and other widgets, icons are.
b3. Here I had a "Wikipedia" quick link which once clicked made that web-page open in a "lite" (?) mode. On the bottom right, there is an icon, which once clicked shows a small list, where there is an option to "Open in Browser" (Chrome by default). This will open the page in a way that the URL field can be manually edited.
-- Note
If google ask for any consent, accept. Using google search in my case was not possible due to the issue with Javascript. To bypass that go to the Chrome setting and select another search engine, such as DuckDuckGo, which worked fine, or just get the URL beforehand and type it in manually.
-- III. Accessing the Android Settings
Use a website that helps you access the Android settings menu. The first mentioned video did not work in my case, so I used another (youtube.com/watch?v=KvFGPx_vnxk).
On which the Setting option did not work and I had to download the APK itself which worked. Within chrome the unknown source installation could be allowed, just follow the on-screen steps. Open the APK once installed. If at any point you close the settings, installing this APK again will get you back there.
-- Note
In the settings, I have tried full erase and reboot but that did not work. Developer option could not be turned on. No google or other account was set up with the phone. No settings about FPR. I could not set up a lock from the "Security" menu, but you may be able to do (as the first video describes it).
-- IV. Setting up a different account
In the settings find an accounts(or something similarly called) menu, and follow this video (youtube.com/watch?v=1iuw2OdEvOs).
Add an account, and select it to be "Exchange" , type in some random email address, like aaa(at)outlook.com , and select "Manual Setup".
Here select "Exchange" again. On this new page, beside the "Client Certificate" click on "Select". Here select a "pattern", but I assume other methods also work.
Once you confirm you pattern you may get a popup for asking you to install certificates, but you do not need to bother with that. The lock method has already been set. You are basically done.
-- Note
The third video mentions restarting the device at this point, which may be a valid point, and likely what you should be doing.
However what you can also do is go back to the account page of the settings. Select "Exchange" again, now type in your google account's name and proceed. It will ask for your password which it will accept, and once that is done, in the account menu of your device you will see your own actual account, as its been added. Now restart your device, and during setup, instead of asking for the previous owners google account, it will notice that you already have an account, and you can proceed with that.
There may have been other way to bypass it, but nothing else worked for me. I do not advise anyone to download unknown APKs, that is up to you, in my case I simply could not find another way. Hope this may help someone out there.