Open a database already created by DT on DTTG

[BLUEFROG]

Welcome @mauog
Firstly, You should not be synchronizing the same database to multiple cloud services.

Secondly, we don’t recommend using a remote sync option unless it’s needed. See…

Sync Types Explained

First Questions Sync is simple but you need to choose the type of sync method to use. Regarding syncing, the first question you need to ask yourself is, “Do I need a remote sync option?”. Consider these questions… Do you need to sync between machines – especially desktop Macs – in different geographic locations? Do you have a colleague, assistant, significant other, etc. that needs frequent updates to synced data? Are you using a shallow sync, i.e., Download Files: On demand in DEVONthink To …

Thirdly, while we do not advocate for any particular service, Dropbox has been a more reliable performer over time than iCloud syncs, e.g., CloudKit.

Lastly, just installing DEVONthink To Go won’t make it magically start syncing your databases. That is a decision YOU must make, not the software. Syncing is always optional and there are many situations where a person could have databases they don’t want to sync.
You need to go into DEVONthink To Go’s Settings > Sync: Locations, properly set up the sync location, then tap it, and choose the databases to import.