Unable to update a Custom Field that my own Forge app created

Forge
9

@kkercz I have now changed the code to add the issue first and then update it. The add works fine, the update fails with OAuth 2.0 is not enabled for method: PUT /rest/api/2/issue10045. Here’s my code:

//  insert the issue
var body_data = <some structure that works>;
var response = await api.asApp().requestJira(route`/rest/api/3/issue`, {
    method: 'POST',
    headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
    },
    body: body_data
});  
var t1 = await response.json();
//  this works, issue is created OK

//  update the just-created issue with the value
var custom_field_identifier = stored_info.custom_field_info.schema.custom;
var bodyData = '{ "fields": { "' + custom_field_identifier + '": "' + api_body.column_value + '" } }';
var r1d1 = await api.asApp().requestJira(route`/rest/api/2/issue${t1.id}`, {
    method: 'PUT',
    headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
    },
    body: bodyData
});
var t2 = await r1d1.json();

The stored-info structure is just something I save when the app is installed, to use later.

And here’s the manifest, for the custom field:

jira:customField:
- key: my_external_id
name: My External ID
description: The external ID for this Issue
type: string

I’ve tried this with two different formats of the field key, one you’ve suggested here and the one shown here. Both give me the same error - the OAUTH 2.0 thing.

What am I doing wrong? Please help!