I think he wants to have the button redirect to the actual job posting URL at another website.
@vanchalakhotia
That is already possible. You just need to enter the URL in the field where you could normally also add the Email.
Go to Job Listings > Settings > Job Submission you’ll find a setting called Application method. This let’s you control what a user can submit via the job submission form. Set it to one of the following:
Email addresses only – Employers must enter a valid email address for candidates to apply via.
Website URLs only – Employers must enter a valid URL for candidates to apply via.
Email addresses or Website URLs – Employers can use either of the above.
Depending on whats used (URL or email) determines how the “Apply for job” area looks on your site – it will show either a mailto: link, or a website link.
https://wpjobmanager.com/document/customising-job-application-process/