Read more on MDN
let create: ( WebAPI.CredentialManagementAPI.credentialsContainer, ~options: WebAPI.CredentialManagementAPI.credentialCreationOptions=?,) => promise<WebAPI.CredentialManagementAPI.credential>
let get: ( WebAPI.CredentialManagementAPI.credentialsContainer, ~options: WebAPI.CredentialManagementAPI.credentialRequestOptions=?,) => promise<WebAPI.CredentialManagementAPI.credential>
let preventSilentAccess: WebAPI.CredentialManagementAPI.credentialsContainer => promise< unit,>
let store: ( WebAPI.CredentialManagementAPI.credentialsContainer, WebAPI.CredentialManagementAPI.credential,) => promise<unit>