deployment/apim-policies/Refreshes the access token.xml

<policies>
    <inbound>
        <base />
        <set-backend-service base-url="{{identityServerBaseUrl}}" />
        <rewrite-uri template="/connect/token" />
        <set-header name="Content-Type" exists-action="override">
            <value>application/x-www-form-urlencoded</value>
        </set-header>
        <set-body>@{
            var requestBody = context.Request.Body.As<JObject>(preserveContent: true);
            var refreshToken = requestBody["refreshToken"];
            return $"grant_type=refresh_token&refresh_token={refreshToken}&client_id={{clientId}}";
        }</set-body>
    </inbound>
    <backend>
        <base />
    </backend>
    <outbound>
        <base />
        <choose>
            <when condition="@(context.Response.StatusCode == 200)">
                <set-body>@{
                    var refreshTokenResponseObject = context.Response.Body.As<JObject>(preserveContent: true);
                    return new JObject(
                        new JProperty("token", 
                            new JObject(
                                new JProperty("accessToken", refreshTokenResponseObject["access_token"]),
                                new JProperty("refreshToken", refreshTokenResponseObject["refresh_token"]),
                                new JProperty("expiresIn", refreshTokenResponseObject["expires_in"])
                            ))
                    ).ToString();
                }</set-body>
            </when>
        </choose>
    </outbound>
    <on-error>
        <return-response>
            <set-status code="@(context.Response.StatusCode)" reason="@(context.Response.StatusReason)" />
            <set-header name="Content-Type" exists-action="override">
                <value>application/json</value>
            </set-header>
            <set-body>@{               
				return new JObject(
					new JProperty("errorCode", context.Response.StatusCode.ToString()),
					new JProperty("errors", new JArray(new JObject(
							new JProperty("errorTarget", context.LastError.Reason),
							new JProperty("description", context.LastError.Message))))
				).ToString();
			}</set-body>
        </return-response>
        <base />
    </on-error>
</policies>