Hi there and welcome
To do this
Open a web browser on your personal computer and go to the Manage your Kindle Page
If necessary, log in.
Scroll down to view the e-books in your Kindle Library.
Hover the cursor over the Actions button for the e-book you'd like to loan.
If loaning has been enabled for the e-book, a Loan This Title option appears.
Click the Loan This Title option.
Enter the person’s e-mail address and name as well as a message.
The borrower of the e-book receives an e-mail from Amazon. The borrower has seven days to accept the loan by clicking the Get Your Loaned Book Now button provided in the e-mail.
Let me know how you go please