1) Buy the B211A visa extension here on this page. You have the choice between regular processing time and express.
2) After checkout you will get the link where you can enter your data.
3) One of our employees will contact you via WhatsApp or email.
4) You will give us your passport or we will pick it up personally or by Go-Jek.
5) We will prepare the documents and submit your passport to immigration for renewal.
6) You will get an appointment for photo + fingerprint at the immigration (you have to be present in person).
7) After about 14 working days the extension should be completed and our employee will pick up your passport with the extension stamp at Immigration. We will bring the passport personally or by Go-Jek to your accommodation.

You can get the B211A extension here.