I have to install wp bakery page builder in WordPress site and fetching page into frontity but UI isn’t working there, I did already import bakery JS and CSS file into frontity header but still not working.
Apologies for the delay in getting back to you on this.
WP Bakery is, TBH, not a great page builder plugin. The problem with it is that it adds lots of shortcodes to the page content, as you can see in your screengrab. These shortcodes will appear in the content.rendered property of the post/page so Frontity will just render these shortcodes as part of the content.
If it’s possible for you to do so for your project I would suggest using Elementor if you need a page builder plugin. Elementor does not add shortcodes to the content, in the way that WP Bakery and other page builders like Divi do.
Which will return the rendered content from Oxygen in the REST response with the post/page results.
And in Frontity all you have to do is check if ‘content_oxygen’ is filled and otherwise use the default ‘content.rendered’ result.
I do not not know how WP Bakery works, but the concept should be the same.