There is no way to merge accounts as different types of login create different addresses.
The alternative is to setup Aggregate Verifier where multiple sub-verifiers are combined under one single aggregate verifier, and one wallet address is generated from the aggregate verifier. You can combine multiple login methods to create a verifier to get the same address for your user regardless of their login providers while creating a verifier, for example, combining a Google and Facebook to access the same key for your user. These login methods should share the same Verifier ID, e.g., email ; such verifiers are called Single ID Verifiers . Please refer to: