Change size of iframe code

I used an embed block to add an iframe code, this one: <iframe src="https://www.solcellekraft.no/whitelabel/eb8c647b-ce20-4e5e-9918-1cb7d5c2a92b" style="border-width:0" allowtransparency="true"></iframe> 

But I cannot manage to change the size of the window?

Any idea? 

Thanks 

Try change your code to

<iframe src="https://www.solcellekraft.no/whitelabel/eb8c647b-ce20-4e5e-9918-1cb7d5c2a92b" style="border-width:0" allowtransparency="true" width="500px"></iframe>