Prerequisites: 

user accounts are created manually in AD

they sync to Okta from AD

set up Effy: Freshservice Provisioning app in Okta as per Freshservice advice (sync user info from Okta to Freshservice + other things)

the app assigns by the group Everyone

Every user in our tenant that syncs from AD to Okta automatically should get an assignment of Effy: Freshservice Provisioning app. Looks like users do sync properly from AD to Okta but sometimes we're getting the following error:

An error occurred while provisioning Effy: Freshservice Provisioning

Automatic provisioning of user ____ to app Effy: Freshservice Provisioning failed: Error while creating user user@domain.com: Bad Request. Errors reported by remote server: Please fix this on the Tasks Page

It doesn't show what is the exact issue.

Was able to solve this issue for 2 other users just by adding Department in AD (previously there was a - dash sign). After it synced from AD to Okta, was able to assign the app. Sometimes several attempts to assign help.

For the current user (new account) tried multiple times to assign the app from Tasks, and info looks OK

Are there any mandatory fields that have to be added?

We also have some service accounts that do have a similar issue but it's not necessary for them to be assigned with this app.

Tried comparing it with other new users and it looks almost the same (the affected user has no primaryPhone attribute but I don't think that is the issue)