Missing thumbnail for 3Speak videos

3Speak posts lack a thumbnail when shown in condenser feeds.

Example post body:

<center>\n\n[![](https://img.3speakcontent.online/zeqcwiuj/post.png)](https://3speak.online/watch?v=wehmoen/zeqcwiuj)\n\n▶️ [Watch on 3Speak](https://3speak.online/watch?v=wehmoen/zeqcwiuj)\n\n</center>\n\n---\n\nIn this video I show you how to use the new login system for the creator studio.\n\n---\n\n▶️ [3Speak](https://3speak.online/watch?v=wehmoen/zeqcwiuj)

Spoke to @quochuy on Slack. He asked me to assign this issue to him.