I personally use ACR Recorder (Android Phone) I have not upgraded to Android 9 Pie since google removed the permission to record phone calls in the updated OS.
I AM NOT A LAWYER and I am not qualified to provide legal opinion on the subject matter, however I personally refer to this article when determining whether or not to record a phone call I am involved in: "Section 184 of the Criminal Code prohibits wilful interception of private communications, but provides an exception if one of the participants consents to that interception. Basically, that means if you consent to record your own conversation, it’s perfectly legal. If you can’t get your own consent, you may be breaking the law." Quoting from https://criminal.findlaw.ca/article/can ... ersations/
Which I understood that I do not have to notify the other party I am recording the phone call.