How to change default page slug?

I have a CPT called jobs and a page named Job Apply. I am trying to achieve something like below url:

Where, job-slug can be any job. i.e Programmer, Developer etc..

On clicking job’s apply button, it should open an apply page which consists a simple form, but url should be as mentioned above.

I am trying to achieve it by using add_rewrite_rule(), but after trying too much, it is still redirecting me on the below url:

Any help would be appreciated. Thanks in advance.