I was having the same issue but I was able to do resolve it since my website is hosted on in-house server. So I connected to our private network wifi and was able to save the snippet.
Hi @faisalahammad
First of all Thank you so much for your reply.
There was some script injected through some plugin(All in one something)
We have cleared the files and site is up and running since yesterday till now its working fine hopefully it will continue to do so. We have installed Wordfence and increased the security as well
We are closely monitoring the site.
Thank you so much again.
