I am upgrading my v8.1.4 site to v10.0.0

I created a new v10.0.0 umbraco project and connected it to a copy of the v8.1.4 database. Everything seems to have migrated as expected. I made all the code changes to make v10.0.0 work.

The issue I'm having is I cannot log in as any already existing member. If I create a new member, I am able to log in. But pre-existing members cannot log in without changing their password.

Is there some setting I have to add to v10.0.0 appSettings.json to use these old passwords? From what I've found online, the machineKey is used to create the hashed password in v8.1.4, but I haven't found a way to add it to appSettings.json.

I would like to just verify these existing passwords if that is possible.

Thanks in advance!

MachineKey from v8.1.4

<machineKey validationKey="..." decryptionKey="..." validation="HMACSHA256" decryption="AES" />

MembershipProvider from v8.1.4

<add name="UmbracoMembershipProvider" type="Umbraco.Web.Security.Providers.MembersMembershipProvider, Umbraco.Web" minRequiredNonalphanumericCharacters="0" requiresUniqueEmail="false" minRequiredPasswordLength="10" useLegacyEncoding="false" enablePasswordRetrieval="false" enablePasswordReset="false" requiresQuestionAndAnswer="false" defaultMemberTypeAlias="Member" passwordFormat="Hashed" allowManuallyChangingPassword="true" />