Welcome to the community.
What do you mean by custom page? Could you please clarify?
Page like where I can create my own fields and could design it according to my requirement. I have attached the snapshot below for the reference.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
If it is a team-managed project, Customize an issue's fields in team-managed projects.
If company-managed project, you have to create custom fields and then add them to relevant screens. Configure issue custom fields Before you do that I recommend taking a look at this admin guide: Administer Jira Cloud products
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.