Help Sending Image Post-Hire

I’ve already stored the reference photo on my iPhone/iPad and I’d like to hand it over only after I’ve officially hired a freelancer here on the platform. What I need is a clear, fool-proof walkthrough—preferably written in plain language—for how to attach and send that image inside the project’s private chat once the contract is active.

Please show me exactly which buttons to tap in the iOS app (or in Safari if that’s simpler), how to confirm the file has uploaded, and any common pitfalls to avoid so the image arrives in full resolution. If annotated screenshots or a very short screen-recording make the steps clearer, include them.

Acceptance will be based on:
• A concise step-by-step guide that works on an iPhone or iPad.
• Visual aids (screenshots or a quick clip) that match each step.
• Confirmation tips so I can see the file sent successfully.

That’s all I need—once the instructions work, the job is done.