How to customise the Cognito OIDC Sign-In prompt?

Hello, thank you for your inquiry. Please see below our AWS guide to customizing the Cognito sign-in and sign-up webpages for the hosted UI:

• https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-app-ui-customization.html

Any other desired customization may be done through the creation of a custom UI. Also, through our AWS What's New and AWS News blog will you be able to keep track of any customization requests for the service:

• https://aws.amazon.com/new/?whats-new-content-all.sort-by=item.additionalFields.postDateTime&whats-new-content-all.sort-order=desc&awsf.whats-new-analytics=*all&awsf.whats-new-app-integration=*all&awsf.whats-new-arvr=*all&awsf.whats-new-blockchain=*all&awsf.whats-new-business-applications=*all&awsf.whats-new-cloud-financial-management=*all&awsf.whats-new-compute=*all&awsf.whats-new-containers=*all&awsf.whats-new-customer-enablement=*all&awsf.whats-new-customer%20engagement=*all&awsf.whats-new-database=*all&awsf.whats-new-developer-tools=*all&awsf.whats-new-end-user-computing=*all&awsf.whats-new-mobile=*all&awsf.whats-new-gametech=*all&awsf.whats-new-iot=*all&awsf.whats-new-machine-learning=*all&awsf.whats-new-management-governance=*all&awsf.whats-new-media-services=*all&awsf.whats-new-migration-transfer=*all&awsf.whats-new-networking-content-delivery=*all&awsf.whats-new-quantum-tech=*all&awsf.whats-new-robotics=*all&awsf.whats-new-satellite=*all&awsf.whats-new-security-id-compliance=*all&awsf.whats-new-serverless=*all&awsf.whats-new-storage=*all

• https://aws.amazon.com/blogs/aws/

If you happen to have anymore questions regarding the service, please do not hesitate to reach out to our team.