How do you figure out the bass notes when transcribing a song?

I have recently started transcribing, I don’t have perfect pitch or anything but i can find the melody quite easily. However, I don’t know which bass notes to use and I can’t pick them up with my ears, any help? Hope I can put some tabs here in the future

I use a program called ‘Transcribe!’. It has a ‘note guess’ feature which gives you a keyboard layout and marks the key of the note it thinks is being played at the current place in the song. Its not perfect but its usually more than enough to help.

I’ll try it out thanks