Warning: Undefined array key "_form_id" Warning issue during job application submission

[jhouedanou]

Bug
A user encountered an error while attempting to submit a job application. The error message "Undefined array key '_form_id'" appears when the user clicks on the "Apply" button. This issue prevents the user from successfully submitting their application.
However the application is registered on the backend
Using WP Job Manager Application 2.3.0

To Reproduce
Steps to reproduce the behavior:

1. Navigate to the job application page.
   2 . Fill in the necessary details in the application form.
2. Click on the "Apply" button.
3. See error ( ! ) Warning: Undefined array key "_form_id" in D:\wamp64\www\bralico\wp-content\plugins\wp-job-manager-applications\includes\wp-job-manager-applications-functions.php on line 104

Screenshots

Expected behavior
I expect the process to go through
Isolating the problem (mark completed items with an [x]):

• I have deactivated all the other plugins and confirmed this bug occurs when only WP Job Manager plugin is active.
• This bug happens with a default WordPress theme active.
• I can reproduce this bug consistently using the steps above.

WordPress Environment

• WordPress Version: 6.5.3
• WP Job Manager Version: 2.3.0
• PHP Version: 8.1