Apply for S1-form
You live abroad and continue to work in the Netherlands. Therefore, you need an S1-form. You can apply for an S1-form below.
For some countries you need an S1-form
You can prove in your country of residence that you pay your insurance premium in your country of employment (the Netherlands), using the S1-form. You can only apply for an S1-form if you already live abroad. Not when you are in the process of moving to your new address abroad.
In all other countries outside the EU/EEA and treaty countries, your insurance card is sufficient.