There's an app for that

Save and import:

{
    "createdBy": "Redirector v3.5.3",
    "createdAt": "2023-06-01T00:00:00.011Z",
    "redirects": [
        {
            "description": "Reddit to Beehaw",
            "exampleUrl": "https://reddit.com",
            "exampleResult": "https://beehaw.org",
            "error": null,
            "includePattern": "^(https?://)([a-z0-9-]*\\.)?reddit.com(.*)",
            "excludePattern": "",
            "patternDesc": "Reddit to Beehaw",
            "redirectUrl": "https://beehaw.org",
            "patternType": "R",
            "processMatches": "noProcessing",
            "disabled": false,
            "grouped": false,
            "appliesTo": [
                "main_frame"
            ]
        }
    ]
}