hi @Davlat - did you buy the equipment brand new from a Cisco/meraki reseller? If not, its more than likely that those devices are sat in someone else's dashboard already claimed.
You need to contact whoever you purchased them from and ask them to unclaim from their dashboard.
Meraki support can't help you in this instance.
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.