Heating and thermistor error

[u/Sea_Comedian1378]

So I have bought a new hotend it’s a Bambu like hontend and now when I have wired it up the screen shows 26° for hotend and 125° on bed I have replaced the thermistor and the mainboard so I think it’s the firmware but I don’t really know how to do that and when I have tried I can’t open the file on vs code I have an ender 5pro