Of course.
If you had a bank, credit union, security company, or even just a safe, would anyone have the right to tell you you must store and protect someone else's property for them? Would anyone have the right to tell you you couldn't provide that service for someone you wanted to provide it for?
Of course not.
Who has the right to tell you who you can/can't lend money to? Borrow money from?
No one has that right.