Check whether a job offer or recruiter is a scam

Help me check whether this job offer or recruiter might be a scam.

What they sent: [paste the message, advert or offer, removing my personal details]
How they contacted me: [e.g. WhatsApp out of the blue, a job site, email]
What they've asked for: [e.g. payment, bank details, passport, to download an app]
What I've already sent or paid: [anything]

Ask me up to 3 short questions first if anything important is missing. Wait for my answers.

Then:
1. The warning signs in what I've pasted, each with one line on why it matters.
2. Anything that looks normal for a real employer.
3. Safe ways to check: finding the company myself (not through their links), calling a number I find independently, and checking the company is real.
4. What not to send until I'm sure.
5. If I've already paid or shared details: tell me to contact my bank straight away and report it to Report Fraud (the UK's fraud and cyber crime reporting service).

Calm and practical. Don't say it's definitely fake or definitely real. Only use what I've told you, leave blanks for anything I haven't given, and don't invent facts or figures. UK English.

Stay in this ChatGPT chat. Do not turn on apps or connectors, and do not use memory from another chat.