Unable to add custom scripts using content web part on SharePoint Online
Solution: – Enable Custom Script in the SharePoint Online Global Level.
Control whether users can run custom script on personal sites and self-service created sites. Note: changes to this setting might take up to 24 hours to take effect. For more information, see http://go.microsoft.com/fwlink/?LinkId=397546
Prevent users from running custom script on personal site
Allow users to run custom script on personal sites
Prevent users from running custom script on self-service created sites
Allow users to run custom script on self-service created sites
Content Editor/Script Editor starts appearing
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