With iOS and iPadOS, you can use the Notes app to add signatures to documents on an iPhone, iPad, or iPod touch. Here’s how:
° Open Notes, then tap the document in the note.
° Tap the Share button, then tap Markup .
° Tap the Add button, then tap Signaturel and add a saved signature or create a new signature. Then you can adjust the size of the signature box and place it wherever you want on the document.
° Tap Done.
To manually sign your document, follow steps 1-2, then select a tool to use and sign the document with your finger or an Apple Pencil with a compatible iPad.
(This how-to is based on my experiences and info on Apple’s support pages — where the images sometimes come from.)