To add a new component you need to have "Administer project" Permission in your project
To select a component when creating an issue make sure the components are added by project administrator and then make sure you have Edit issues permission.
In simple words check whether you are the project administrator for the project and whether you can edit other issues also in that project.
If you are Project administrator, you should be able to add new components, otherwise contact Jira administrator about this and for selecting components while editing an issue make sure components are present in the components page link in project sidebar.
For JSM June Challenge #2, share how your non-technical teams like HR, legal, marketing, finance, and beyond started using Jira Service Management! Tell us: Did they ask to start using it or...
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