twitter api v2 to capture random sample of a specific language

Question

I can't believe this is not a common/often considered query to the twitter v2 API

We are looking for a sample of tweets in a specific language (we're testing language translation tech) e.g. english or spanish.

There exists a sample end point, there exists a search query end point, however sample endpoint doesn't seem to allow to attach a query. The search query doesn't seem to allow an 'empty search string', on which can add the language specifier

we've tried things like (as no real clues in the docs, so these do fail as expected)

curl --request GET 'https://api.twitter.com/2/tweets/sample/stream?lang:en' 

curl --request GET 'https://api.twitter.com/2/tweets/search/recent?query=lang:en' 

curl -X POST 'https://api.twitter.com/2/tweets/search/stream/rules' \
-H "Content-type: application/json" \
-H "Authorization: Bearer <TOKEN>" -d \
'{
  "add": [
    {"value": " lang:en"}
  ]
}'

and also things like

"'{
  "add": [
    {"value": "from: * lang:en"}
  ]
}'

we could query the sample, include the language field and then dismiss all we are not interested in, but given we need large volumes, this will waste quotas.

Anyone accomplished this?