The correct repository is https://github.com/wso2/kubernetes-ei and not https://github.com/ThilinaManamgoda/kubernetes-ei. Sorry for the mistake. Yes, these Kubernetes resources are pointed to Docker images which are hosted at WSO2 docker registry which you need a WSO2 subscription to pull. If you are planning to use free images then you have to do followings,

Remove Image pull secret definition by commenting in each deployment yaml files. For example, in Integrator deployment yaml it’s these two lines[1], [2]
Point Docker hub in each deployment yaml file instead of docker.wso2.com. For example, in Integrator[3] change docker.wso2.com/wso2ei-integrator:6.4.0 to wso2/wso2ei-integrator:6.4.0
Remove creating wso2creds secret from the deploy.sh script. For example, if you're going to try integrator-analytics pattern then comment this line[4]

[1]https://github.com/wso2/kubernetes-ei/blob/bbbdfe53e98b2d9beaef915e6f5ceee79712e3b7/integrator-analytics/integrator/integrator-deployment.yaml#L73
[2] https://github.com/wso2/kubernetes-ei/blob/bbbdfe53e98b2d9beaef915e6f5ceee79712e3b7/integrator-analytics/integrator/integrator-deployment.yaml#L74
[3] https://github.com/wso2/kubernetes-ei/blob/bbbdfe53e98b2d9beaef915e6f5ceee79712e3b7/integrator-analytics/integrator/integrator-deployment.yaml#L34
[4]https://github.com/wso2/kubernetes-ei/blob/bbbdfe53e98b2d9beaef915e6f5ceee79712e3b7/integrator-analytics/scripts/deploy.sh#L80