@azizmashkour : can you please update to use Bootstrap 4.1?
https://blog.getbootstrap.com/2018/04/09/bootstrap-4-1/

Thank you!

Are you having issues with Bootstrap 4.1? Is this fully functional on Bootstrap4?

have pulled locally and does not work properly with 4.1 in current state. Fails to open anything if only one step, and then even with 2 steps it opens but there is no title or content

Having had a play with the source, I think the issue for lack of title and content is due to the default template, currently it is

template: '<div class="popover" role="tooltip"> <div class="arrow"></div> <h3 class="popover-title"></h3> <div class="popover-content"></div> <div class="popover-navigation"> <div class="btn-group"> <button class="btn btn-sm btn-secondary" data-role="prev">&laquo; Prev</button> <button class="btn btn-sm btn-secondary" data-role="next">Next &raquo;</button> <button class="btn btn-sm btn-secondary" data-role="pause-resume" data-pause-text="Pause" data-resume-text="Resume">Pause</button> </div> <button class="btn btn-sm btn-secondary" data-role="end">End tour</button> </div> </div>',

but it should be

template: '<div class="popover" role="tooltip"> <div class="arrow"></div> <h3 class="popover-header"></h3> <div class="popover-body"></div> <div class="popover-navigation"> <div class="btn-group"> <button class="btn btn-sm btn-secondary" data-role="prev">&laquo; Prev</button> <button class="btn btn-sm btn-secondary" data-role="next">Next &raquo;</button> <button class="btn btn-sm btn-secondary" data-role="pause-resume" data-pause-text="Pause" data-resume-text="Resume">Pause</button> </div> <button class="btn btn-sm btn-secondary" data-role="end">End tour</button> </div> </div>',

Note I have just changed the classes
popover-title
popover-content

to
popover-header
popover-body

I can confirm that @BenMaxfield solution solves the issue with Bootstrap v4.1+

@azizmashkour @BenMaxfield @asseti6

Thank you for all of your work that you've done! It helped a ton today for me. I posted a gist that uses all this goodness here:

https://gist.github.com/peteristhegreat/0678620341f6af725b23cd4cd395ec48

It is working for me as well. You did an incredible job, thank you !

Thank you all guys, I will definitively recheck and retest all submitted pull requests in the repository then prepare a new version that will contain all new features and fixed issues.