Your registration file is below. Save it into a YAML file and give the path to that file to synapse:

id: {{ .Values.appservice.id }}
as_token: {{ .Values.appservice.asToken }}
hs_token: {{ .Values.appservice.hsToken }}
namespaces:
    users:
        - exclusive: true
          regex: "@{{ .Values.bridge.username_template | replace "{{.}}" ".+"}}:{{ .Values.homeserver.domain }}"
url: {{ .Values.appservice.address }}
sender_localpart: {{ .Values.appservice.botUsername }}
rate_limited: false