How to configure FreePBX to send moh and Invite with a:sendonly

I have FreePBX (with Asterisk 16.6.2) and I would like to know how to configure FreePBX so when a call A puts call B on hold, FreePBX sends music on hold AND an Invite to B with a:sendonly.

By default, when A puts B on hold, B hears music on hold. But FreePBX continue to send SDP with a: sendrecv.
If I configure moh_passthrough=true on pjsip.endpoint_custom_post.conf (as suggested in other topic), FreePBX sends an Invite to B with a:sendonly (and B answer with a:recvonly) but B doesn’t hear any music on hold.

How to configure so I have both behaviors: B hear music on hold and FreePBX sends an Invite to B with a:sendonly?

*consider both users are in LAN (internal)

There is no support for doing that in Asterisk.