The version of the Campaign Manager works only with the SMS-Magic Converse base package 1.58.25 and above
Admin users, non-admin users, and community users must be assigned with the newly introduced “Campaign Launcher Permission Set” in order to use Campaign Manager.
To use Campaign Manager, all the users will have to first configure the remote site settings for the respective endpoint URL.
Steps to register remote site setting
Open Campaign Manager
2. Copy the domain URL
Add this URL to the remote site setting at Setup->Security->Remote site settings->New Remote Site.
And save.
If your SMS-Magic Converse base package version is Spring 2021 and above, users should be assigned with a License having access to the Campaign Manager feature.