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 "{userid}" ".+"}}:{{ .Values.homeserver.domain }}"
          {{- if .Values.appservice.communityID }}
          group_id: {{ .Values.appservice.communityID }}
          {{- end }}
    aliases:
        - exclusive: true
          regex: "@{{ .Values.bridge.alias_template | replace "{groupname}" ".+"}}:{{ .Values.homeserver.domain }}"
          {{- if .Values.appservice.communityID }}
          group_id: {{ .Values.appservice.communityID }}
          {{- end }}
url: {{ .Values.appservice.address }}
sender_localpart: {{ .Values.appservice.botUsername }}
rate_limited: false
