Looking for discount voucher for solutions architect associate SAA-C03

You just missed the Free exam retake promotion.

I got the practitioner about 2 yrs ago

There is a free recertification option for AWS Certified Cloud Practitioner at https://explore.skillbuilder.aws/learn/course/external/view/elearning/17623/aws-cloud-quest-recertify-cloud-practitioner

Are there any promotion

Usually, you get a 50% off exam discount voucher after passing, which you can use for your next exam. Login at https://www.aws.training/Certification and go to Benefits section to claim your voucher code.