After adding issues to Agile Project its often convenient to save the loaded issues configuration as a project. Next time you load the project the Issues are refreshed and new ones or deleted ones in the JQL are added/removed.
Please note that Jira issues are never saved outside your Jira Instance. Only misc info such as project name, issues id and JQL are saved to enable fetching the Issues when loading.
In Jira cloud saving projects is only available opening the app from the “Apps Menu”.