Copy a Custom field value in "Request participants" field automatically

[Houssein Barkallah]

I have been trying to copy the value of a text (multiple line) custom field into the "Request participents" field.
I also tried using JIRA MISC WORKFLOW EXTENSIONS to copy the field, but it doesn't work and I get this error in the excecution log: 

Incorrect request: {"customfield_10026":"Could not find usernames: unknown"}

Please help me out with this issue. Thanks!

[Nic Brough -Adaptavist- · Accepted solution]

Welcome to the Atlassian Community!

Request participants is a calculated field, you should not be trying to set it with an app.

[Houssein Barkallah]

Hi Nic,
I tried working with Jira automation, but it doesn't allow the copy 😢 ( only user type fields are available while the custom field source is text )
And I couldn't manage to retieve the information I desire from the request

[John Funk]

Hi Houssein  - Welcome to the Atlassian Community!

You should use the email address of the user. 

[Houssein Barkallah]

Hi John and thank you for your reply.
Sorry if I wasn't very specific;
I have an app that manages my emails and creates issues according to some rules (Email this issue)
I'm trying to retieve this information from newly created JSM issues that are coming through email ( email CC) and put them in the Request participants field.

[John Funk]

Who is listed as the Reporter for the newly created issues? 

[Houssein Barkallah]

The Reporter field takes the sender of the email.

[John Funk]

Which is who you want to be added to the Request Participant field - correct? 

If that's the case, then you can do an automation rule to copy the value of the Reporter field into the Request Participants field. 

[satya.mynampati]

I’m in the same situation where I want Custom field (email) value to be copied to request participant field. but 

I don’t see the similar option what your showing in the screen shot. I have the option like below

Could you please suggest.