This board is for iPhone installation and update questions. Identify the installation method as well as the app: instructions can differ between a signed app, a sideloaded build and a jailbreak-specific setup.
Start with the provider's current installation instructions. For iPogo, the provider lists its supported installation routes on its own site:
https://ipogo.app/
Before changing an installation, back up anything important and check your recovery options:
https://support.apple.com/guide/iphone/back-up-iphone-iph3ecf67d29/ios
Record your iPhone model, iOS version, app version, installation method and exact error. Do not post Apple Account credentials, signing certificates, provisioning files, device identifiers or subscription keys.
An instruction to install a management profile or trust a developer changes what you are allowing on your device. Verify who provides it and what it does before proceeding. Advice about an organization's enterprise deployment is not automatically appropriate for a personal app installation.
This board provides independent community discussion. Provider subscriptions, signing-account access and billing questions should go to that provider's private support.