How To EnableDisableManage Your WhitelistAllowlist
On Java versions of the game, the whitelist is called "whitelist" and on Bedrock it's called "allowlist". The commands are exactly the same, but the command starts differently. /whitelist on - This command is for Java. /allowlist on - This command is for Bedrock.
If your server has crossplay enabled (supporting both Bedrock and Java editions), some players may have spaces in their usernames (typically Bedrock players). In such cases, use the following command to add them to the whitelist:
/whitelist add "Your Username"
Make sure to enclose the username in quotation marks ("").