As an Agile practitioner, how can I get a higher salary?

Why are you asking about this? Should you be an Agile purist? :)

Alright, just kidding.

Like in every industry, you will be rewarded for doing a good job. A good job usually means you can help your company increase revenue, reduce costs, and deliver products people love. You will be contributing from very different perspectives depending on your current role. If you're a Scrum Master, you want to be able to build a super team and lead the team to work in a manner to increase revenue, reduce cost, and deliver products that people love. If you're a Transformation Lead, you should be able to create a super multi-team work system that increases revenue, reduces cost, and delivers products that people love for your company.

So, please note the keywords: increase revenue, reduce cost, and deliver products that people love. Justify your company ROI by having you in these three perspectives. If you're doing a good job, and your ROI is visible and measurable, asking for a raise should be a readily justifiable event.

Please note that the following does not sound like an ROI to your company:

1. "I've been a Scrum Master for X years"
2. "I have got a ridiculous number of Agile certificates."
3. "I can do a lot of technical Agile practices, like TDD, BDD, FDD, DDD, etc."

Well.

What can you actually do? What have you done that's significant?

What have you achieved that impacts your company revenue, operation cost, and product success?

Please think from the perspective of your company and your boss. Stop self-justifying because you are so-called "Agile."