If you check at the above, The Netherlands isn’t listed. That’s the reason why you are getting a greyed out button.
If you were connected to Gemini earlier there’s some hope if Uphold doesn’t support Netherlands in the future.
There’s a flag in Brave Nightly called ‘always show Brave rewards custodial connection options’ which once comes to Brave stable release probably somewhere in February or March, will allow to enable the buttons and try connecting and see if it allows you to connect even if Region is unsupported.
Also you should check out for more updates →