Open the camera PNI 550C with SIM and SD card Inside
Try to add it into the APP Tuya
if you didn't succed then
Connect the camera to the computer
You will find the file tmp_apnuser.csv
Edit the file and complete the next informations.
and save
Restart the camera and it myst work.

Note: When we can not get Internet accessible successfully, maybe it is caused by APN setting error. 
For guiding users to set APN, an instruction file will be generated in the card for reference.
The file name is "tmp_apnuser.csv", can be opened by Excel. Entries are following.
IMSI: the content is filled in automatically. If not, check it on camera main interface.
APN: ask the SIM card operator for obtaining
Username: ask the SIM card operator for obtaining
Password: ask the SIM card operator for obtaining
Timezone: never mind
Operators: never mind
Country: never mind
Auth: 4 types of SIM card authentication. Ask the SIM card operator for obtaining. 0: not required, 1£ºPAP,  2£ºCHAP,  3: PAP or CHAP.
Note: After modifying "tmp_apnuser.csv" in original file, must rename it as "apnuser.csv" , then restart and dial to TEST mode.
Wait 1 minute for restart, then the file "apnuser.csv" will be deleted automatically.
Check it again, if the "apnuser.csv" is deleted in the card, it indicates the sucess of update.ÿÿ