ThrottlingException when requesting Appstream streaming urls

If you're running into throttling, I would suggest reaching out to your AWS account team to work with a solutions architect to dive in and understand your use case to ensure the right architecture. They can ensure that your call volume is expected, and propose alternatives (for example, spreading load across multiple AWS accounts, or using multiple regions).

If not what's the recommend way of proceeding when we get such exception, Wait before retry? any specific algorithm or wait times suggested that could help to mitigate this issue?

To directly answer this question, the recommendation is to use exponential backoff with jitter. You can learn more here: https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/