Here's the scenario:
You've booked some gear under your name, but someone else is paying for the hire. Where can you find a payment link to send them so that they can pay online?
This is no problem. Here's what to do.

Go To The Job In Your Rental History

Find the job in your rental history (you did remember to add your own meaningful reference, of course!).
If there is a balance owing for the job, you will see a Copy payment link button with the other job buttons, above the list of equipment being hired. See the screenshot below.
Click the Copy payment link button to copy the link to your clipboard.
Clicking the Copy payment link button generates a link and copies it to your clipboard. You can then send the link however you choose - SMS, email, Slack, WhatsApp, etc.
The link that is generated is to a secure page where anyone can pay for the hire using a credit/debit card, Google Pay or Apple Pay. If they're not the one paying either, they can pass the page on with the Share this page button.
The payment link allows anyone to pay for a job.
Job done 👍.