How to scan documents on your iPhone
/Scan and attach a document to an email
You can scan a paper document and send it as a PDF.
Tap in the email where you want to insert the scanned document.
Tap the icon above the keyboard that looks like a document with four corners around it.
Position iPhone so that the document page appears on the screen—iPhone automatically captures the page.
Tap Retake or Keep Scan, scan additional pages, then tap Save when you’re done.
For further instructions, visit https://support.apple.com/guide/iphone/add-email-attachments-iph8580f163b/ios.