Raspberry Pi 3 b+ Dragino PG1301 free uart serial port for enabling GPS

I have spent some time investigating how to enable GPS module which I get with LoRa concentrator board Dragino PG1301. I am using Raspberry Pi 3b+ and I know that it has two UART serial ports and GPS should be connected via UART0 which is by default used by Bluetooth. How should I free that UART port from BLE and connect GPS? I have documentation that says what to do but not how:
http://www.dragino.com/downloads/downloads/LoRa_Gateway/PG1301/PG1301_UserManual_v1.0.4.pdf
And also I have a problem that when I ran minicom it opens terminal but nothing goes one and I can not do anything, not even to kill the process so I have to exit terminal completely. I am configuring raspberry pi 3 using the ssh protocol. Thank you in advance

Best regards
Ivan

The instructions you refer to point to google to find instructions on how to switch the serial port to uart in stead of bluetooth. Did you google?

In about 1 minute I found this site with useful information.

Thank you Jac, yes I have found solution like this and tried but I do not have idea how to check if gps is active after this because I can not open a file /dev/ttyAMA0 with minicom. How shoud I check if gps is active. In ttn data json response it doesn’t say anything about coordinates. Thank you

If the packet forwarder is not running, you should be able to open the serial port, unless the system is not yet actually configured to make that port work.

If the packer forwarder is running, presumably you’d see something about GPS in whatever log is capturing the packet forwarder messages.