When I configure special hop entry: "receive" using the Postman request:
"Add special hop ipv4"
and then get operational data using:
"Get routes operational"
the new entry exists under "learned-protocol-0" instead of the specified "test-routing-protocol-3"

Also VAT dump shows the entry having a "vrf-id" of 0 instead of the desired value 3

Configuration through VAT works as intended:
ip_add_del_route 192.168.2.5.32 via 0.0.0.0 vrf 3 local create-vrf
will create a new vrf table with the specified entry.