Here's an easy template you can send:
Hi,
I've been using a company called Tally Market to easily book flexible workspace for me and my team and I thought you might benefit from their service. They have thousands of great coworking venues available on their platform and you can book desks, meeting rooms and private offices by the day.
If you register and include my email address in the 'Referred by' field, then once you've bought 100 tokens, they'll give us both an extra 20 each (worth £100).