In order to log into your personal investor portal, you need to go to the domain URL of the platform you are investing through. You can find this domain as part of a contribution page you are investing through, or by asking your platform manager what the URL is.
An example of a platform URL:
After navigating to the domain URL of the platform you belong to, you need to connect your wallet to the platform and sign in. You can sign in through Metamask, or a variety of other wallets through WalletConnect.
After signing the transaction that pops up for connecting to the platform, you can see your investor portal, which contains everything you need to know about your investments. If you are missing an allocation in your portal, it might be because it belongs to another account.