Some ad blockers and privacy filters, for example uBlock Origin, are currently blocking access to analytics.amplitude.com
We have requested that Amplitude's website is removed from the block list but in the meantime you may need to manually unblock the website to access it.
For uBlock Origin you can unblock the site by clicking the extension icon and then clicking the "power" button. See here for details: https://github.com/gorhill/uBlock/wiki/How-to-whitelist-a-web-site#click-the-big-power-button
If you need help with a different blocker or have any other questions please reach out to our platform team at https://help.amplitude.com/hc/en-us/requests/new