Hello,
Are you currently connected to a VPN?
If so, please temporarily disconnect from the VPN and switch your internet connection from Wi-Fi to a mobile hotspot. Then, check whether you can download the apps from the Microsoft Store.
If you are still having issues,
Try running the network troubleshooter by going into Settings > Troubleshoot > Other troubleshooter >Network and internet.
- Once the troubleshooter is finished running, restart your Computer.
- Press Windows + R, type wsreset.exe and click Ok.
- Try installing the app from the Microsoft Store.
If you are still having issues, change the DNS Server -
- Press Windows + R, type ncpa.cpl, and click Ok.
- Right-click your default Wi-Fi adapter and select Properties.
- Click 'Internet protocol version TCP/IPV4 > Properties'.
Change the DNS Server address -
Preferred DNS server: 8.8.8.8
Alternate DNS server: 8.8.4.4
Click Apply and then Ok.
Then, restart your computer and install the apps from the Microsoft Store.
Let me know if you still need more help.