The party moving to compel arbitration bears the burden of proving that the parties entered into an arbitration agreement. Here, plaintiff employee denied that she had electronically signed the arbitration agreement during the employment onboarding procedure that defendant implemented on taking over the acute care facility at which plaintiff worked. One way to authenticate an electronic signature is to show that it could be affixed only through use of a unique personal id and password known only to the signer. (Civ. Code 1633.9(a).) Defendant had not used such a system during the onboarding process. Applying the substantial evidence rule, this decision finds ample evidence to support the trial court’s finding that defendant’s supervisory employees onboarded new employees including plaintiff in a rush to complete the process, and that they rather than she electronically signed the arbitration agreement.