<PackageReference Include="System.ServiceModel.Primitives" Version="8.0.0" />

System.ServiceModel.Security.SendSecurityHeaderElementContainer

public void MapSecurityTokenToStrClause(SecurityToken securityToken, SecurityKeyIdentifierClause keyIdentifierClause)

public bool TryGetIdentifierClauseFromSecurityToken(SecurityToken securityToken, out SecurityKeyIdentifierClause keyIdentifierClause)