To add a custom record to your ENS name, open the name’s profile editor by clicking Edit profile
Next, click on the + Add more to profile button.
On the "Add profile fields" window, click Other. Then select the Custom, and click the Add button to create your custom record.
Type the name of the custom key into the first input box under Custom. Next to it, input the value you would like to save for the custom record and click Save.
On the next window click Open Wallet to confirm and sign the transaction. Your custom record will then be added to your ENS name!
Add a Custom Service Key
Some types of ENS records use a key name formatted in "reverse dot notation". These are known as "Service Keys" as specified in ENSIP-5.
For example, you want to save your YouTube channel name in your ENS records. To create a custom record for the YouTube account service, simply name the key com.youtube and set its value to your YouTube channel name.
On the next window click Open Wallet to confirm and save the custom Service Key and its value to your ENS records. Now a record for YouTube.com will exist for your ENS name!
There is no limit to the number or types of records you can create for your ENS name.