Anonymous/pseudonymous telemetry doesn't necessarily require user consent other than for being polite. If you store PII you do, but if you do that you also aren't really doing anonymous/pseudonymous telemetry to begin with.
Read the replies elsewhere. GDPR doesn’t care about whether a http request containing an IP is necessary or not. The GDPR is not in any way regulating how or why any PII is “transmitted” out of your system.