Asp.Net Core 3.1 Seed data with conditionally

I don't want to seed if the data exist in the modelBuilder.

Here is I tried and seeded again with different role ids so my user with the roles has gone.

    protected override void OnModelCreating(ModelBuilder builder)
    {
        base.OnModelCreating(builder);

        builder.Entity<IdentityRole>().HasData(
            new IdentityRole { Name = "Admin", NormalizedName = "Admin".ToUpper() },
            new IdentityRole { Name = "PoUser", NormalizedName = "PoUser".ToUpper() },
            new IdentityRole { Name = "User", NormalizedName = "User".ToUpper() }
        );

    }

So how can I prevent data seeding with conditional rendering in Asp.Net Core 3.1 if data exist in the db ?

Thanks