It’s not recommended but it is possible, so long as the other plugin has exported the function. In the .h where the function is declared, it needs to be preceded with OTHERPLUGINMODULENAME_API.
If that’s the case, you need to include that header from your plugin, and also add the following to your plugin’s build.cs file.
PublicDependencyModuleNames.Add("OtherPluginModuleName");