Want to buy

[bob3160]

And its ok  for laptop? And how can i buy it?

https://www.avast.com/en-eu/secureline-vpn#pc

[DavidR]

Then why it show's 36£ year, and 2,99£ month?

It is just an example of what it effectively costs per month, for Antivirus Versions you can't purchase anything less than a year. 
Your (massive ) image shows what you are billed for 'Billed as £35.88 / Year'

Other than for the Avast Secureline VPN, the exception as has been mentioned.

[rocksteady]

Antivirus, my bad, sorry

You have said here tat you wanted Antivirus.
Secureline VPN is not Antiviris, so it is not applicable to your immediate need.
Suggest you use free version of Avast Antivirus if you only want it for 1 or 2 months.

[schmidthouse]

Antivirus, my bad, sorry

You have said here tat you wanted Antivirus.
Secureline VPN is not Antiviris, so it is not applicable to your immediate need.
Suggest you use free version of Avast Antivirus if you only want it for 1 or 2 months.

I'm not sure exactly what the OP is wanting to buy/use. However it seems the info for either has been provided.