LPAs can be made online or using paper forms. In either case, you need to get other people (your attorneys, witnesses, and certificate provider) to sign the same original forms. They can’t sign copies of the forms or use digital signatures.
We would recommend that you use a solicitor to advise you upon your LPA instructions, draw up the documents, arrange for these to be executed by all the necessary parties in accordance with the strict legal requirements, and then register these.