wifi issues with rtl8822be on Ubuntu 18.04 LTS

Question

I need your help for an issue I meet on my laptop Asus Vivobook S14. I installed Ubuntu 18.04 LTS and erased Windows 10. Everything is working except Wifi.

Here's some useful informations about my wireless card:

louisa@louisa-X411UQ:~$ lspci -knn | grep Network -A3
02:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. Device [10ec:b822]
    Subsystem: AzureWave Device [1a3b:2950]
    Kernel modules: r8822be

louisa@louisa-X411UQ:~/Documents/wifi/rtlwifi-next$ sudo lshw -class Network
  *-network NON-RÉCLAMÉ     
       description: Network controller
       produit: Realtek Semiconductor Co., Ltd.
       fabriquant: Realtek Semiconductor Co., Ltd.
       identifiant matériel: 0
       information bus: pci@0000:02:00.0
       version: 00
       bits: 64 bits
       horloge: 33MHz
       fonctionnalités: pm msi pciexpress cap_list
       configuration: latency=0
       ressources: portE/S:d000(taille=256) mémoire:ef100000-ef10ffff
  *-network
       description: Interface réseau sans fil
       identifiant matériel: 1
       information bus: usb@1:1
       nom logique: wlx1062eb94abf1
       numéro de série: 10:62:eb:94:ab:f1
       fonctionnalités: ethernet physical wireless
       configuration: broadcast=yes driver=rtl8xxxu driverversion=4.15.0-23-generic firmware=N/A ip=192.168.0.14 link=yes multicast=yes wireless=IEEE 802.11

My kernel version :

louisa@louisa-X411UQ:~$ cat /proc/version
Linux version 4.15.0-23-generic (buildd@lgw01-amd64-055) (gcc version 7.3.0 (Ubuntu 7.3.0-16ubuntu3)) #25-Ubuntu SMP Wed May 23 18:02:16 UTC 2018

I got this repository : https://github.com/rtlwifi-linux/rtlwifi-next but when I try the make command I meet this error :

louisa@louisa-X411UQ:~/Documents/wifi/rtlwifi-next$ make
make -C /lib/modules/4.15.0-23-generic/build M=/home/louisa/Documents/wifi/rtlwifi-next modules
make[1] : on entre dans le répertoire « /usr/src/linux-headers-4.15.0-23-generic »
Makefile:976: "Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel"
  CC [M]  /home/louisa/Documents/wifi/rtlwifi-next/base.o
/home/louisa/Documents/wifi/rtlwifi-next/base.c: In function ‘_rtl_init_deferred_work’:
/home/louisa/Documents/wifi/rtlwifi-next/base.c:461:2: error: implicit declaration of function ‘setup_timer’; did you mean ‘sk_stop_timer’? [-Werror=implicit-function-declaration]
  setup_timer(&rtlpriv->works.watchdog_timer,
  ^~~~~~~~~~~
  sk_stop_timer
cc1: some warnings being treated as errors
scripts/Makefile.build:332: recipe for target '/home/louisa/Documents/wifi/rtlwifi-next/base.o' failed
make[2]: *** [/home/louisa/Documents/wifi/rtlwifi-next/base.o] Error 1
Makefile:1552: recipe for target '_module_/home/louisa/Documents/wifi/rtlwifi-next' failed
make[1]: *** [_module_/home/louisa/Documents/wifi/rtlwifi-next] Error 2
make[1] : on quitte le répertoire « /usr/src/linux-headers-4.15.0-23-generic »
Makefile:100: recipe for target 'all' failed
make: *** [all] Error 2

The command sudo modprobe r8822be returns this:

louisa@louisa-X411UQ:~$ sudo modprobe r8822be
modprobe: ERROR: could not insert 'r8822be': Required key not available

and the dmesg | grep 8822 command returns nothing.

I would be relieved if someone could tell me how to solve this problem.

Thank you everyone