Have you looked into Zelle? You'll need a bank account that has access to online banking and is enrolled with Zelle (I think most are). It looks like, if you bank participates, and you have access to (or use) online banking, you can enroll with your bank credentials/email account.
If your bank or credit union offers Zelle, you may be able to use their online banking site to send and receive money without a mobile device. If your bank or credit union does not offer Zelle, then you must have a smartphone in order to access the Zelle app to send and receive money.
Now, I haven't actually ever signed up with this service or explored it very far, but I am constantly reminded by my banks that this is a feature I can take advantage of.
If this isn't an option, I'll second asking someone else with Paypal/Venmo to handle the collections.