As found here, you must replace every occurrence of archive.raspberrypi.org or mirrordirector.raspbian.org by legacy.raspbian.org, which is an official site.

Source: software installation – Why doesn’t Raspbian apt-get resolve package version correctly? – Unix & Linux Stack Exchange

Source: ADSLPPPoE – Community Help Wiki

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = Analog Modem
ISDN = 0
Modem = /dev/ttyUSB2
Baud = 9600

[Dialer thenet]
Phone = *99***1#
Username = thenetuser
Password = thenetpw
; Username = 9180****** (If your provider use without Username)
; Password = 9180****** (If your provider use without Password)
Stupid Mode = 1
Baud = 460800
Init3 = AT+CGDCONT=1,"IP","apn.thenet.net"

[Dialer mypin]
Init4 = AT+CPIN=1234

Source: Wvdial – ArchWiki

Create the wvdial config file

• The next step is to create a config file for wvdial so you can connect to your service provider.
• Open a terminal window and enter:

sudo leafpad /etc/wvdial.conf

• Replace the content of the file with the following.

[Dialer 3gconnect]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Init3 = AT+CGDCONT=1,"IP","internet"
Stupid Mode = 1
Modem Type = Analog Modem
ISDN = 0
Phone = *99#
Modem = /dev/gsmmodem
Username = { }
Password = { }
Baud = 460800

• Replace internet with your service provider’s APN
• Replace the Phone number if you need to dial a different code to connect.
• Replace Username and Password if needed. To leave the username and password as blank use { }

Source: How to setup a USB 3G Modem on Raspberry PI using usb_modeswitch and wvdial | How To | The Fan Club | dynamic design solutions

Source: “AT command” in the Huawei e3372h-510,i need help 🙁 – Huawei Enterprise Support Community

Stick info

ATI

Queries device information

> ATI
< Manufacturer: huawei
< Model: E3372
< Revision: 21.180.01.00.00
< IMEI: XXX
< +GCAP: +CGSM,+DS,+ES

AT^VERSION?

Query firmware versions.

> AT^VERSION?
< ^VERSION:BDT:Sep 30 2014, 15:17:21
< ^VERSION:EXTS:21.180.01.00.00
< ^VERSION:INTS:
< ^VERSION:EXTD:WEBUI_17.100.18.05.1217_HILINK
< ^VERSION:INTD:
< ^VERSION:EXTH:CL2E3372HM Ver.A
< ^VERSION:INTH:
< ^VERSION:EXTU:E3372
< ^VERSION:INTU:
< ^VERSION:CFG:1004
< ^VERSION:PRL:
< ^VERSION:OEM:
< ^VERSION:INI:

AT^TBATVOLT?

Query battery voltage (not applicable for the E3372 as it is a USB-powered stick, but probably returns the USB voltage).

> AT^TBATVOLT?
< ^TBATVOLT:4458

AT^CHIPTEMP?

Query the chip temperature.

> AT^CHIPTEMP?
< ^CHIPTEMP: 304,304,65535,27,65535

SIM info

AT+COPN

Query known/supported network names.

> AT+COPN
< +COPN: "732123","Movistar"
< +COPN: "73402","DIGITEL GSM"
...

AT+CPOL?

Query preferred roaming networks.

> AT+CPOL?
+CPOL: 1,2,"26202",1,0,1,1
....
+CPOL: 62,2,"40443",1,0,1,1

AT^ICCID?

Query the ICCID (SIM card number).

> AT^ICCID?
< ^ICCID: 8931XXXXXXXXXXXXX

AT^CPBR?

Query the SIM phone book.

> AT^CPBR=?
< ^CPBR: (1-250),40,20
> AT^CPBR=1
< ^CPBR: 1,"+XXXXXXXXX",145,"XXXXXXX",0

Connection info

AT^PLMN?

Query the connected network code (MNC/MCC).

> AT^PLMN? 
< ^PLMN: mnc,mcc

AT^LOCINFO?

Query network location info.

> AT^LOCINFO?
< ^LOCINFO:XXXXX,0xXXXX,0xXX,0xXXXXXX

AT^CREG?

Query registration info, which contains (among other things) the cell ID.

< AT+CREG?
> +CREG: 2,1,"XXXX","XXXX"

AT+COPS?

Query network operator info:

> AT+COPS?
< +COPS: 0,0,"NAME OF MNO",7

AT^CSNR?

Query signal-to-noise level.

> AT^CSNR?
< ^CSNR: -145,-32

AT^CERRSI?

Query received signal strength indications (RSSI).

> AT^CERSSI?
< ^CERSSI:0,0,0,0,255,-90,-7,15,32639,32639,32639

AT^DSFLOWQRY

Query flow (traffic) statistics.

> AT^DSFLOWQRY
< ^DSFLOWQRY:00000010,0000000000060A85,000000000003CC18,00000010,0000000000060A85,000000000003CC18

Source: GitHub – pixelspark/tymodem: Read status from Huawei E3372 modem using AT commands

Source: internet – Ubuntu 20.04 and Huawei Mobile Stick E3372 – Ask Ubuntu

Source: Huawei E8372 Linux Configuration and Setup · GitHub