USPS no access to delivery location means that the UPS mail carrier was not able to access your location or mailbox to deliver the package to you.
This could be because of a locked gate, blocked mailbox, ice on a sidewalk leading to your house, dangerous dog etc.
Make sure the pathway to your house or mailbox is cleared and accessible and if you have a locked gate make sure it's open when the mail carrier comes by.
Also make sure your mailbox is cleared of snow, ice etc and that the USPS mail carrier has access to deliver your package.
You may have to call your post office and ask what happened.
You may also be able to just go to the post office and pick up the package.
However I've had this happen to a few packages and it turns out the mail carrier was trying to deliver it to the wrong address and so I called them and they delivered the package to the correct address the next day.
There are many reasons why your package was tagged as “Delivery attempted - no access to the delivery location”.
It may be your mailbox is already full and they couldn’t put new mail inside.
Or it may be that something is blocking your mailbox such as a car parking in front of it, the mailman may tag your package as “No Access”.
Or it could be the post office employee has the problem, he might be behind schedule so he’s gonna tag your package/mail as “No Access”.
Most of the reason why this happens is also due to the weather condition in your area.