The moment someone opens his or her mouth and the words "foot strike" come out, just tell whoever it is to get to the part where they try to sell you something. It's inevitable, so do away with the preamble and get right to it. Why waste time? There are miles to be run.
Whatever it is, you probably don't need it. If there was one thing in the running industry that has been wildly overstated in value, it is foot strike; what used to be of passing interest to coaches and the odd eccentric is now a magical unicorn that every single runner seems obsessed with to the point of fetishism. We have almost become proud of needing to change our foot strike beyond the point of considering if we even need to in the first place.
You don't. Really and truly. I do not even know you, but I am 99% certain your foot strike is just fine assuming you aren't overstriding. Your ankles? Well, that's a different story.