If you have an array you can:

set txt(1)="1
set txt(n)="n

ClassMethod write(txt As %ArrayOfDataTypes)
  set​ arg1=$get(txt(1))
  set arg2=$get(txt(n)


  set l="" for i=1:1 {
         set l=$order(txt(l))
         set arg(i)=txt(l)​​​​​​


and call it with the array ByRef:

do ..write(.txt)

After enabling Audit and enabling the specific Audit events I could see the reason for the login failures.

Error message: ERROR #800: Logins for Service %Service_WebGateway are disabled
Web Application: /api/atelier

After starting the WebGateway Service I was able to log in.

@Alexander Koblov : Thanks for the tip - I did this already but didn't enable the specific events. So I could see nothing. Thank you.

I have the IRIS Community Edition license for Red Hat. Funny is that the  IRIS Windows Community Edition works like a charm.

Here is the license key for the Red Hat Edition. Everything looks good.

License Capacity  InterSystems IRIS Community license
Customer Name  InterSystems IRIS Community
Order Number  54702
Expiration Date  10/30/2021
Authorization Key 8116600000500000500008000084345EF8F2473A5F13003
License Type=Concurrent User
Platform=IRIS Community
License Units=5
Licensed Cores=8
Authorized Cores=8
Extended Features=3A5F1300
- Interoperability
- BI User
- BI Development
- HealthShare
- Analytics Run
- Analytics Analyzer
- Analytics Architect
- HealthShare Foundation
- Analytics VR Execute
- Analytics VR Format
- Analytics VR Data Define
- InterSystems IRIS

  Unfortunately I have no login for WRC and can not get a preview license to test.