Is there any free whiteboard for online Math tutoring?

My advice to you would be to try LiveBoard. The free version has some limitations, yet it allows you to use the premium account features as a free trial. They include limitless boards and video tutoring features. You can connect your Zoom account and graph editor to your LiveBoard account and classes and insert graphs using formulas right on the spot during your course. This feature is helpful especially for math because, in many cases, a lot of the confusion among students comes from unclear visuals during classes. When these visuals are created in a matter of seconds, it saves you the trouble of misunderstanding and visually appealing lessons that make your courses more understandable and attractive. It provides you with helpful tutorials and additional guides, so in all, it is not hard to use. It also has a great blog full of insightful tips, and the majority of the time, articles are on essential topics for people both in and outside of the tutoring field. Give it a try; it might be what you need!