Hi, thanks for your quick answer. I found a solution, which fits my skills: I created another Zotero account, got a new zotero-ID. Then I found out how to add my new profile in zotero, having now two Zotero-profiles. Then I started Terminal on my Mac to add the new profile in zotero.
macOS
Open Terminal via Spotlight or /Applications/Utilities.
Paste /Applications/Zotero.app/Contents/MacOS/zotero -P into the Terminal window.
Press Return
Windows
Open the Run dialog (Search/Cortana → type “Run” → Run (Windows 10) or Start → Run (Windows 7)
Paste C:\Program Files (x86)\Zotero\zotero.exe -P
Press Enter
Next step was to take off the hook on “use the selected profile without asking at startup” – which is good – I can choose which profile on zotero I want to work, when I start zotero.
With my second zotero profile I got a new ID for my second library. I added this library ID in zotpress. It works now perfect.
Best
