Can't connect sftp/ftp to access wordpress

Hi, I'm using Ec2 to ran my wordpress website. I can't login and access my wordpress, maybe plug in issue. I tried to connect sftp/ftp to access wp_content, but putty and Filezilla shows error that server refused key, I think I lost the initial key pair .pem file, even I created new key and update to ssh , I still can't connect sftp or ftp to access the wp_content.

I had asked the wordpress, they told me that I should ask hosting to connect the ftp .

How can fix this issue and access to wp_content ? Thanks