How to grow my event website?

Hello,
I'm working on an event website for one specific target audience in one country.

We're seeing some initial tracktion, mostly from Google and cold email outreach to event organizers.
The cold email outreach works ok, but it quite time consuming.

Our most important growth factor at the moment would probably be, to get more organizers to sign up and post their events on our website.

What are your ideas for experiments on growing into that direction?

20 - 40 visitors each day
1k+ cold...

How to grow my event website? WordPress ...