Parameter SolutionPrefix failed to satisfy constraint:

[antoncloud]

Hi there, its very good repo to exercise but not working. I tried to create stack but not allowing me to create. The following is the error : Parameter SolutionPrefix failed to satisfy constraint: Only allowed to use lowercase letters, hyphens and/or numbers. Should start with 'sm-soln-explaining-' for permission management. Should be 39 characters or less. Will you please help me? I am new to IAC and AWS. I look forward to hearing from you. Thanks