302 Redirect with chan_pjsip

Hello everybody

I try to send a SIP 302 on an incoming call. In my Dialplan I have
exten => 9876,1,Transfer(PJSIP/0123456 [at] tel.t-online.de) or
exten => 9876,1,Transfer(PJSIP/0123456 [at] endpoint-telekom)
where 9876 is my landline, 0123456 should be my mobile phone and endpoint-telekom is an endpoint in pjsip config working well for in- and outbound calls.

PJSIP sends a 302, but I think it’s not correct.

SIP/2.0 302 Moved Temporarily
Via: SIP/2.0/UDP provider.ip:5060;rport=5060;received=provider.ip;branch=z9hG4bKg3Zqkv7i3sw8rwfkwie5x51ozxbmu2ct2
Record-Route: <sip: provider.ip ;transport=udp;lr>
Call-ID: p65546t1583049206m524138c534429437s2
From: <sip: cid-of-caller ;user=phone>;tag=h7g4Esbg_p65546t1583049206m524138c534429437s1_1570638174-670976882
To: <sip:9876 [at] telekom.de;user=phone>;tag=0891e1a3-d84b-4929-92f8-f420f576dfee
CSeq: 1 INVITE
Server: Asterisk 13
Contact: <sip: 0123456 [at] my.public.ipv4:5060>
Reason: Q.850;cause=0
Content-Length: 0

It looks like the call is redirected to my landline again instead of my mobile, because after some seconds the call comes in with a new call-id.

So my question is, how to configure the dialplan to send a correct 302 redirecting to my mobile phone?

Thanks in advance.

I did further research, but only found examples using chan_sip.

Anybody any idea about correct syntax of Transfer() with PJSIP?