This is just an extra information injected in PeerTube HTML that is required by Twitter/X. If you don't have a Twitter/X account, just leave the default value.
This is an <x id="START_TAG_STRONG" ctype="x-strong" equiv-text="<strong>"/>import<x id="CLOSE_TAG_STRONG" ctype="x-strong" equiv-text="</strong>"/> tool and not a migration tool. It's the reason why data (like channels or videos) is duplicated and not moved from your previous PeerTube website.