How can I do certification of Azure with low cost.

Through LinkedIn, I found out about Microsoft virtual training days. Here's a link: https://www.microsoft.com/en-us/trainingdays By registering & attending Azure sessions they offered a FREE voucher for the AZ-900 Fundamentals exam. I believe they still offer vouchers for the various fundamental categories. I just had to sit through a few virtual sessions, review lots of material available on LinkedIn Learning & elsewhere, then drive to the exam facility at our local college....and YES I passed the exam & now studying for the next one AZ-104 where I see I can get a 1/2 off voucher. So for my first certification, AZ-900 I didn't invest anything except our most valuable resource.....time.