Translation:Can we pay for a one-way ticket to the moon for him?
No, I don't think that works.
payer is transitive (it takes a direct object) and can mean "to pay" or "to pay for".
So, "We pay him" is On le paye/paie - le is the direct object; and "We can pay him for the work" is On peut le payer pour le travail - le is the direct object, le travail is the indirect object.
"We can pay for a one way ticket..." = On peut payer un aller simple ...; un aller simple is the direct object.
"We can pay for a one way ticket for him..." = On peut lui payer un aller simple ...; lui is the indirect object ("for him") and aller simple remains the direct object.
I think actually the suggested translation is different (i.e. wrong) from what is written and implied in french... Can we pay him... is different from Can we pay a ticket for him... right? And I think what is written is 'Can we pay him..." (and there is no Report button with this excercise!)
Yes, I agree, once it was translated I saw the intention that I should have spotted before but a simple translation is 'Can we pay him.." It's obviously not that because why would anyone pay for a one-way ticket if it wasn't to get rid of someone else! I'd love to visit the moon but I'd want to come back!