Amendment and h1b extension

I moved from location A to location B which is different location and my employer has not filed amendment and it’s been 18 months and my current I 797 is valid until July 2019, can I file amendment with h1 extension together.

What would be the consequences I need to face.

Yes, you should file it. You may or may not receive an RFE, why it was not filed…This has to be worked with your attorney and carefully dealt. Speak and work with them.