So we now support the ability for Supreme users to add external URL's to their Ticket Embeds.
This can be done on the panel under https://panel.parent.gg/ - once you're logged in, click "Tickets & Embeds".
Then find the related embed you want it on, and click "Edit"
Once done on the "Display" button, select it and click "External Button". This prompts you three options.
Once done, remember to re-send the embed. This is a supreme only feature.