Secure API Key and AI App Deployments

I’m looking for a freelancer to help protect my API key and secure my AI app deployments across Vercel, Github,Google AI Studio, and Bolt.ai.
I have already moved the relevant URLs and projects from AI Studio and Bolt.ai to GitHub and imported them into Vercel. I now need someone
Protect my API key is not exposed.
Check for insecure handling of environment variables, client-side leaks, or public references.
Recommend and explain the corrections needed.
Leave clear written instructions so I can personally make the remaining changes on my other URLs.
Work on only one Vercel account, one AI Studio project, and one Bolt.ai project as a reference case, not across all my projects.
I am specifically looking for someone who can guide me step by step, not just make changes silently.
Please note:
No direct changes to all my projects without approval.
No sharing of API keys beyond what is strictly necessary.
Clear documentation of every change made.
Experience with Vercel environment variables, secure deployment, and API key protection is required.
If interested, please reply with:
Relevant experience.
How you would protect sensitive keys during the work.
Whether you can provide written instructions for me to apply to the rest of my URLs.