Auto accept certificate

How to make a script to send files and auto accept certificate instead of putting in script a key which can change?
For example to skip this in script and auto accept and connect ssh-rsa 2048 xxxxxxxxxxx...=:

You can use -hostkey=*:
https://winscp.net/eng/docs/scriptcommand_open#hostkey

But you should not do it! Verifying the hostkey (it's not a certificate) is an integral part of SSH security. By blindly accepting any hostkey, you become vulnerable to MITM attacks. Your server's host key should not change. If it does, it's a security weakness.

thank you for info.
I don't have any that much important data. I use this just to send some files over internet.
Problem is, when sending files stops to work when certificate changes and I don't know that.
Is there a way to accept certificate only when server name match "myserver" or only for servers with IP - my ip server"123.123.123.123"
This will be much safer.

I do not understand. The -hostkey=* applies only to that open command. So only to the server (hostname or IP) that you specify in the open command.

You said it is vulnerable for MITM attack, when using that.
So how can they do that if I specified IP where to connect?

See Man-in-the-middle attack.