Here's information from the WRTA's website regarding the bus accessibility. https://www.therta.com/elderly-and-disabled/accessibility-at-the-wrta/

And they also offer complimentary paratransit service that allows for more direct service (these do have to be reserved ahead of time though) https://www.wrtaparatransit.com/access-ada-complementary-paratransit-service.htm