I hope you are well today and thank you for your question.
Could you please tell me why you can’t edit it?
Are you getting any errors or anything else?
Also, could you please share your site URL where it’s happening so that I can troubleshoot it?
You have to click on the two buttons as shown in the attached screenshot to use the WPBakery page builder.
Please note that you can only edit the page using the same page builder that you used to create it so if you have used WPBakery or Unyson or Gutenberg or any other page builder then please use the same page builder to edit the page.
Do not switch between page builders or else you will lose the content so choose the page builder that you want to use initially when you create the article content.