You will need the ability to add a custom app to your Teams tenant; this is likely to be a global admin who has this permission. See more in this Microsoft doc: 'Managing custom app policies and settings in Microsoft Teams'.
Also make sure to check the app policies to see if all custom apps are disabled for any of the recipients. Your Teams tenant might "Block all apps" for any third party app and any custom app. If this is the case, add the bot to "Custom apps - Allow specific apps and block all others" as shown in this screenshot below. Changes may take up to 24 hours to take place.