amazon aws: certificates on multiple servers (AWS instances)

We have 1 WHM license (instance in AWS). Within the WHM we create an account. MYDOMAIN.EXAMPLE -This is the MAIN DOMAIN-.

Within the DNS of the EXAMPLE OF MAINDOMAIN We create some examples of subdomains. CLIENT1.MYDOMAIN.EXAMPLE, CLIENT2.MYDOMAIN.EXAMPLE, CLIENT3.MYDOMAIN.EXAMPLE and those are pointing to different instances in other instances of AWS with a "Record A".

In total, we have 7 instances in AWS with different IP, so we have something like this.

CLIENT1.MYDOMAIN.EXAMPLE - IP 192.0.2.1

CLIENT2.MYDOMAIN.EXAMPLE - IP 192.0.2.2

CLIENT3.MYDOMAIN.EXAMPLE - IP 192.0.2.3

CLIENT4.MYDOMAIN.EXAMPLE - IP 192.0.2.4

etc

Each instance has a web server in nginx. Each one has to have 1 certificate …

How can I do this? Is a wild card going to work? Or do I need to buy different certificates for each subdomain?