I own a 2006 Rx 330 with 198k miles on the odometer
any time I switch on the ac and the ac is set to blow to the face only it blows under the dashboard ( on the legs ) and on the face which is not supposed to be happening
what do you think can be done to fix this problem

 

There's a servo under the dash that runs the blend door. Temporarily, you might be able to set it to blow where you want (defrost for instance), turn the car off for the evening, then turn it back on in the morning and have the jolt zing the motor enough to get it to change. This is a very short term fix.
Longer term, look under the dash for the blend motor. Pull yours and if you're on a budget, just order a new motor for inside it from Digikey. Toyota (lexus) likes to use this motor right here for just about everything:
https://www.digikey.com/en/products/...E12AA1/2417070

Here's a guy fiddling with one on Dupe-tube. It's not your model, but will give you an idea of what to look for. They're all generally the same.