DNS TXT when using Letsencrypt

Trying to get my system back up every time I try to use lets encrypt I get this?

Please deploy a DNS TXT record under the name:

_acme-challenge.(MYSITENAME).

with the following value:

F1sd-hzUKFfYlfG7NxWZFMFj21hcFDzeityQOKq_W4w

Before continuing, verify the TXT record has been deployed. Depending on the DNS
provider, this may take some time, from a few seconds to multiple minutes. You can
check if it has finished deploying with aid of online tools, such as the Google
Admin Toolbox: https://toolbox.googleapps.com/apps/dig/#TXT/_acme-challenge.triplesalarm.dedyn.io.
Look for one or more bolded line(s) below the line ‘;ANSWER’. It should show the
value(s) you’ve just added.

And what is your problem, you can’t add the DNS text?

More don’t know how or where.

Where did you get your DNS Name? DynDNS, Noip, something else?

I have tried duckdns.org and dedyn.io both give the same problem

Than check e.g. this one docu for duckdns. You have to do call to duckdns API with your TXT value. E.g. with curl from CLI:

curl https://www.duckdns.org/update?domains={YOURVALUE}&token={YOURVALUE}&txt=F1sd-hzUKFfYlfG7NxWZFMFj21hcFDzeityQOKq_W4w

For dendyn.io you have an example and documentation here.