My site doesnt resolve

Hi, can anyone help? I am new to this and have installed it on my subdomain.But the problem is that the site is not even opening.The PHP memory is already greater than 512M.
https://matomo.chakravyuah.com/

Hi,

There is no DNS entry that points this domain towards an IP address

➜  ~ dig matomo.chakravyuah.com

; <<>> DiG 9.16.8-Debian <<>> matomo.chakravyuah.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36301
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;matomo.chakravyuah.com.                IN      A

;; Query time: 51 msec
;; SERVER: 192.168.188.70#53(192.168.188.70)
;; WHEN: Fr Dez 11 12:21:01 CET 2020
;; MSG SIZE  rcvd: 51

As you already use Wordpress, why not taking the matomo plugin?
512 RAM is rather small in RAM.

Here is a Test blog.kernl.us/2019/03/is-more-ram-or-more-cpu-better-for-wordpress-hosting/
they start with 1gb RAM