Linux does not connect to WiFi in VirtualBox Internal Network

[ElliotA.]

I recently started to study Ethical Hacking based on the book "Ethical Hacking: A Hands-on Introduction to Breaking In"
Following this book i installed three Virtual Machines in VirtualBox: pfSense, Metasploitable and Linux.
Then i attached network adapter 1 of Linux & Metasploitable to the "Internal Network" named "Internal LAN" and pfSense network was attached to "Bridget Adapter" (Adapter1) with the name of my network card (Realtek RTL8723B Wireless LAN 802.11n USB 2.0 Network Adaptet) and (Adapter 2) to "Internal Network".
But the problem is that Linux doesn't connect to the Wired connection 1 (WiFi).
Anyone know how to solve this?