@mariusor I can't provide the full request, but I could say that it had RSA HTTP signature attached.
The inbox was https://federated.id/actors/8b740680-ccb4-4265-82e7-4ac2ca402750/inbox
And the response was 201 Created with empty body.
Here is my unsigned Follow activity:
{"@context":["https://www.w3.org/ns/activitystreams","https://w3id.org/security/
v1","https://w3id.org/security/data-integrity/v1",{"MitraJcsRsaSignature2022":"mitra:MitraJcsRsaSignature2022","mitra":"http://jsonld.mitra.social#","proofPurpose":"sec:pr
oofPurpose","proofValue":"sec:proofValue","sensitive":"as:sensitive","verificationMethod":"sec:verificationMethod"}],"actor":"https://mitra.social/users/silverpill","id":"
https://mitra.social/objects/0188b5b0-829e-aadd-be8d-a5f484fceb34","object":"https://federated.id/actors/8b740680-ccb4-4265-82e7-4ac2ca402750","to":["https://federated.id/
actors/8b740680-ccb4-4265-82e7-4ac2ca402750"],"type":"Follow"}