You can control access to the Lit Actions run by this node in the following ways:

• Groups — Create groups for different categories of actions (e.g. by app or use case). Each group can have its own set of allowed IPFS action CIDs and wallet (PKP) restrictions.
• Usage API keys — Create usage API keys and assign them to pay for Lit Action runs. Use different keys per client or app to track and limit spending. Add keys in the Usage API Keys section and use them when calling the node. Note: your account api key can be also be used as a usage api key, but can not be rotated or removed, so this is not recommended.
• Wallet restrictions — For any group, you can restrict which wallets (PKPs) are allowed to run actions in that group. Add or remove PKPs in the Wallets section (Add PKP to group / Remove PKP from group). You can also set a group to allow all wallets, if you do not need this limit.

In short: create groups, add the IPFS action CIDs and (optionally) the wallets allowed for each group, then use usage API keys to authorize and pay for runs.