You need to make an entry for a borrowed horse event?

Step 1: Go to https://entry.fei.org and login with your FEI credentials.

Step 2: Search for the event in which you wish to make some entries and click on Entries to enter the event

here are the views you will have

This is where you will find all your lists of athletes and horses.

You can search the name in the table or type a name or ID in the white field.

This will show you by default only the registered athletes for the current year and only athletes in the age limits, but you can untick the boxes.

You can then click on "add", your athlete will appear in the "Entry Lists" on the right.

Then select the tab "horses" , click on your athlete's name in the Entry Lists, and after selecting "Will ride borrowed horses", click on on "add"

The OC will be able to enter the horse as soon as the drawn is done.