test.js

TXTextControl.addEventListener("textControlLoaded", async function () {
    document.addEventListener("keydown", logKey);

    async function logKey(e) {
        if (e.key === "F8") {
            const text = await getTextFromSelection();
            const replacedText = await replaceWord(text);

            if (replacedText !== undefined) {
                await loadReplacedText(replacedText);
            }
        }
    }

    function getTextFromSelection() {
        return new Promise(resolve => {
            TXTextControl.selectWord(() => {
                TXTextControl.selection.getText(text => resolve(text));
            });
        });
    }

    async function loadReplacedText(replacedText) {
        const encodedText = btoa(replacedText);
        await TXTextControl.selection.load(TXTextControl.StreamType.HTMLFormat, encodedText);
    }
});