I am trying to configure letsencrypt ssl. Here either we need to do https domain validation or DNS. as my hositng provider does not give .well-known directory to user as it is used for some server configurations so i need to do DNS validation.
But here also I have issue as below
For DNS validation we need to create subdomain with underscore (_) link as below
now underscore () is not valid character for domain names so hosting provider does not allow to create sub domain with (). I check this with few hositng provider all does not allow underscore.
Underscores are already widely used for DKIM and SIP configurations, Let's Encrypt is not using them in a novel way.
The majority of reputable DNS hosts do support their use in these ways.
You will not be able to use the DNS challenge unless your hosts allows it, so you will either need to use the HTTP challenge, or move to another DNS host.