How to add custom thumbnail to Instagram reel

In order to add the custom thumbnail to your Instagram reels

1) Go to Post Composer > Select your Instagram account(s) > Attach the Video/Reel you want to upload.

2) Once the uploading of reel is done, Select "Show options"

3) Scroll down a little, You will see "Attach Thumbnail", Attach the media for thumbnail from your device, Check "Post as Reel" and you are good to go.