Possible to use toneac library on ATtiny85?

Basically wanting to know if it is possible to write in a way for it to work on an attiny85 before I even start to try since I am very new to all of this and how it would be implemented. I am not asking for someone to do it for me, just for guidance on how I can if it is possible. I was thinking since PB0 and PB1 can do PWM it would be possible, I would just need to define those pins in the code somehow. Thanks!

You will have to rewrite the Library to use ATtiny85 timers.
As it is now it use the specific timers for ATMEGA8, 328 and so on.

Timer1 on a Tiny85 is quite different to timer1 on a Mega328.

It should be possible to do, but expect to spend a lot of time reading the datasheet.