Auto scaling group - ASG, error at creation

This is the result of specifying an instance type configuration that does not resolve to instances available in the specified Availability Zones (AZ). To address this, specify instances in your overrides section that show they are available in the specific AZs you plan to use. You can use this CLI command to check specific instance type availability in an Availability Zone - https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-instance-type-offerings.html.

If you are using Attribute Based Instance Selection, be sure to use the console capability to "Preview matching instance types" to ensure that your attributes produce a match to instances. If none are listed, then your configuration needs to be modified and the console will give realtime feedback on the count of matching instances.

You need to check the if Launch Template you are using to create the Auto Scaling Group has the option set for the Instance Type (remember to select the new version when creating the Launch Configuration):

eg.

If you don't want to change the Launch template, you can override the template setting when creating your Auto Scaling Group:

eg.

This is because while you were creating the Template you did not select any Instance Type after selecting AMI.