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In the app, go to Business Settings.
Below Users, click System Users.
Click Add New System User.
Give a name to the system user, and choose the Admin role. Click Create System User.
Click the Add Assets button. Navigate to Apps, select yourApp in assets, and turn on the Manage App switcher. Then click Save Changes.
Click Generate New Token.
Select your app and business_management, whatsapp_business_messaging and whatsapp_business_managing permissions, then click Generate Token.
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