Hi grahamj31943802 ,
Would like to inform that if you would like to create your digital signature you may do that using 'certificates' tools in Acrobat Pro .
Under certificates,select digitally sign option then drag the rectangle over the area where you would like to place the signature after following on screen instructions.
If you would like to places image of your handwritten signature, this is possible using 'Fill & Sign' tool , there under 'sign' you will the option for 'image' using which you select the image of your signature.
Then place that over the document at location where you want.