1. Upload the video to your YouTube account.
2. After uploading, under Visibility, select Unlisted (Anyone with the link can view).
in the YouTube app on mobile:
If you have already uploaded the video and forgot to change the visibility, you can do the following:
1. Go to https://studio.youtube.com/ and open the Content section on desktop, or tap Edit video on mobile
2. Under Visibility, change the setting from Private to Unlisted.