Ec200u-cn https get and post request error code 714 716,732 in at commands

HAI TEAM,
I am using EC200U-CN(UMTS&LTE EVB_V2.2) module when i tried to use HTTPGET i am getting +CMEERROR: 714 [HTTP(S) DNS error], +QHTTPGET: 716 [HTTP(S) socket connect error], +QHTTPGET: 732 [SSL Handshake Failed] .I followed all the process HTTPS Application note & LTE standard HTTPS Application note.How to solve this all error.

ATI
Quectel
EC200U
Revision: EC200UCNAAR02A09M08

OK

AT+CGDCONT?
+CGDCONT: 1,“IP”,“airtelgprs.com”,“0.0.0.0”,0,0
OK
AT+CGDCONT=1,“IP”,“airtelgprs.com
OK
AT+CGACT=1,1
OK
AT+CGPADDR=1
+CGPADDR: 1,“100.105.212.81”
OK
AT+CGDCONT?
+CGDCONT: 1,“IP”,“airtelgprs.com”,“100.105.212.81”,0,0
OK
AT+CGREG=2
OK
AT+CGREG?
+CGREG: 2,1,“D367”,“ABBF716”,7
OK
AT+QHTTPCFG=“contextid”,1
OK
AT+QHTTPCFG=“responseheader”,1
OK
AT+QIACT?
+QIACT: 1,1,1,“100.105.212.81”
OK
AT+QHTTPCFG=“sslctxid”,1
OK
AT+QSSLCFG=“sslversion”,1,1
OK
AT+QSSLCFG=“ciphersuite”,1,0x0005
OK
AT+QSSLCFG=“seclevel”,1,0
OK
AT+QHTTPURL=22,80
CONNECT
OK
AT+QHTTPGET=80
OK
+QHTTPGET: 714
AT+QIDNSCFG=1,“8.8.8.8”,“8.8.4.4”
OK
AT+QHTTPURL=22,80
CONNECT
OK
AT+QHTTPGET=80
OK
+QHTTPGET: 714
+QHTTPGET: 716
+QHTTPGET: 732

Hi there,
From the process, it can be determined that the module injection network is normal, and the steps of HTTPS are also carried out according to our documentation. Please make sure that you enter a valid URL, such as https://www.alipay.com or other HTTPS-enabled Website, in order to improve the correctness of access, it is recommended that you set the encryption suite to 0XFFFF. If you have any questions, please feel free to give feedback, thank you.

Thank you sir, above problem solved give the correct url its working fine. I have another one doubt sir, EC200U-CN linux distrubution that is inbuild linux os is there? how to access linux os in uart my laptop and give root permission (username and password). how to write c code (sdk ) which platform used?
how to compile and test?.