Every mesh gets a URL that looks like the following:
https://<your-mesh>.umesh.co
This is configured within the mesh settings:

You can set this up when you create the mesh or you can edit it later.
Many meshes may only be needed for a short period of time - such as in the lead up to an event. So you are free to change the name and URL of a mesh as needed, or just delete it and create a new one.
When your members access the mesh they will be asked to provide their email address to gain access:

We'll then send them an email with a one-time code.
Once entered, they'll gain access to the mesh without needing to enter another code for a year (assuming they're on the same browser and don't clear their cookies and you don't remove them from the mesh).