You can add your custom function or code that you want to run when you deactivate Job board Manager using this action hook.
if( ! function_exists('job_bm_deactivation_function') ) {
function job_bm_deactivation_function() {
// Your custom Code
}
}
add_action('job_bm_deactivation', 'job_bm_deactivation_function', 10);
