How to query a geographic range without a specific user ID and observation field?

Since this is working now:

https://www.inaturalist.org/observations?nelat=48.1885847&nelng=16.349777000000017&swlat=48.1548561&swlng=16.29185940000002&order_by=observed_on&verifiable=any&place_id=any&not_user_id=1958129

I would like to exclude the observation field inMeidling of that query by adding to the URL:

&without_field:inMeidling

But it does not work:

https://www.inaturalist.org/observations?nelat=48.1885847&nelng=16.349777000000017&swlat=48.1548561&swlng=16.29185940000002&order_by=observed_on&verifiable=any&place_id=any&not_user_id=1958129&without_field:inMeidling

I have tried the field id instead of the name:

&without_field:10878

but this also did not work:

https://www.inaturalist.org/observations?nelat=48.1885847&nelng=16.349777000000017&swlat=48.1548561&swlng=16.29185940000002&order_by=observed_on&verifiable=any&place_id=any&not_user_id=1958129&without_field:10878

What am i doing wrong @jdmore?

Thank you!