https://www.slab.org.uk/faqs/applicants-signatures/
Where you are seeing clients face to face, you must get them to sign the declaration forms.
Clients can also “sign” an electronic version of a paper form by applying a signature using a stylus (for example, iPencil) or other online signing platforms such as DocuSign or Adobe Sign.
Again, the electronic signature must provide sufficient authentication (that is, the signature should be recognisable as the applicant’s signature and not simply an e-squiggle).
You must be able to show an audit trail for the signing process.
In either case you must keep a copy of the “signed” declaration form, either in paper or electronic form.