Hi @Eugenios
You will require an Advanced Security licence for the MX unit at your second site as you can't mix Enterprise and Advanced licences within a single Organisation.
You could create a secondary Org and place the second MX in that and run an Enterprise licence but you'll have to manually create the s2s VPN.
Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/
I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.