AWS not allowing me to switch from on demand instance to reserved instance

Is your account new? Usually, if the account is new, and you didn't have a lot of charges / paid bills on the account yet, you might not be able to buy Reserved Instance or Savings Plan with No Upfront payment option. Maybe, some of the criteria are different, but the bottomline is that the reason is because your account is new.

In any case, open a support case from your account (billing support case), and ask if support can raise this limit or help remove the restriction: https://docs.aws.amazon.com/awssupport/latest/user/case-management.html

Request a service quota increase here:

https://us-east-1.console.aws.amazon.com/servicequotas/home/services/ec2/quotas/L-D0B7243C

Thanks for the input. However, if I am reading the dashboard correctly it says my applied quota value and default quota value are 20. However, I have no reserved instances yet due to the error I am receiving. I have not been able to create any RI as of now. So confused?