Auto Responder on Distribution Group

Hi Experts,

I have a question.

We have some distribution groups use for different purpose like mention on websites and different users are members of these groups. Now we have a requirement to send auto responder when someone from outside the organization send email to group email address like "Thank you so much for you email ... etc"

I have google it and found one way  which is as follows.

Remove the existing distribution group say for example named Group1
Create a new shared mailbox call Group1
Set the auto reply on the shared mailbox as required
Create a new distribution group something else say for example Group1dist and set all the members as required ...   hide from from the GAL
On the shared mailbox setup mail forwarding to forward all mail to Group1dist

Note you don't need to add any members to the shared mailbox as it is just used to auto reply and forward

Unfortunately, all above mention steps are working fine except for auto responder from shared mailbox. i have tried to enable auto responder from both ways admin portal and user settings but none of them is working.

I also tried to achieve through PowerShell method mention on below link

https://www.youtube.com/watch?v=ClUAPl3TcA4&t=181s

But on PowerShell side when use "set" command it generates error. (Error attached)

Please guide me is there any other way to achieve requirement.