fix: avoid double encoding

[wjbeau]

Pull Request Template

Description

Fixes an issue where the arc60 payload was being double encoded

Checklist

• Have you tested your changes locally?
• Have you reviewed the code for any potential issues?
• Have you documented any necessary changes in the project's documentation?
• Have you added any necessary tests for your changes?
• Have you updated any relevant dependencies?

Additional Notes

• Add any additional notes or comments that may be helpful for reviewers.