I will just do this bit. You must be licensed to do PR returns, so that is outside your practice. Have the client contact AirBnB to see if they can refer. Does the activity make a net positive income? A bit of googling would make me think you can probably NOT file PR

https://taxsummaries.pwc.com/puerto-rico/individual/taxes-on-personal-income

.but I would put a burden on the taxpayer to seek other confirmation.