Almost 3 year old will not wear a mask

Hey everyone I have an almost three year old son who absolutely refuses to wear a mask and I’m looking for tips on how to help him wear it.

We haven’t been able to really go out or do anything with him because of the mask mandate, and I have kind of just accepted it, but it’s getting really hard now and I would like to be able to do stuff with him since fall and winter are coming up. During the summer we did all outdoor stuff that didn’t require a mask. We did a lot of virtual stuff with our library last fall and winter, and he really liked it. The librarian would sing some songs and read some books then they would do a craft. The library is no longer doing it virtually and it’s in person, but he’s required to wear a mask so he can’t go. I really am hoping I can somehow get him to wear it in the next few months so he can go to the library.

He pulls it off as soon as we put it on, he won’t wear it for more than a second.

A lot of people have told me to explain to him why he needs to wear it, but he has autism with a significant receptive delay, so the understanding of why he has to wear it is just not there. Does anyone have any tips or tricks?