As some of you maybe remember I tried to write a command which checks a channel if a specific key word exists in its messages. The most crucial part of this code is here:

banlist.messages.fetch({limit : 30}).then(messages => {
            let positive = messages.some(msgs => msgs.content.includes(check))
            if(positive === false) {
               ...
            }
            else{
               ...
            }

Unfortunately the problem arose really quick that this check for the key word is case sensitive. Is there any way to make it case insensitive? I know of the .toLowerCase() but that only works for commands and I dont recall it working for fetched messages. Looking forward to your help :)