We are migrating from UA to GA4. The guide says there's a sampleRate but I can't find any provision to set up sample rate in GA4?
GA4 does not support the setting of the sample rate.
Also, there is no need to place sample restrictions on the data obtained because GA4 has no cap on the total amount that can be collected. This means, even if you are using GA for free, there is no volume cap on the number of logs. Except for certain quotas -
1. More than 10 million events selected in the exploration may be sampled
2. Bigquery allows for a daily import limit of 1 million events.