Yes, of course you can customize and have the opt-in box only on some of your website pages.
How to enable opt-in box only on your preferred webpages.
For HTTPS websites:-
1. Disable global opt-in by clicking on Customize Opt-in under settings on your dashboard
Firstly, disable the global opt-in. You can do so by logging into your PushCrew dashboard. Click on Settings and from the drop-down that appears, click on Customize Opt-in. Now, uncheck Display push notifications permission box. Please refer to the image below.
2 window._pcq = window._pcq || ;
3 window._pcq.push(['triggerOptIn']); //Calls triggerOptIn with default text and default segment(global)\
For HTTP websites:-
1. Click on Customize for desktop under settings
In your PushCrew dashboard, click on Settings. From the drop down that now appears, please click on Customize for desktop.
2. Uncheck Display push notifications permission box
Now, as shown in the image below, uncheck the box that is next to Display push notifications permission box.
Complete documentation on opt-ins can be found in our API documentation page.
This code can be safely deployed with Google Tag Manager or other such tools.