Jodit Editor custom fonts preview on dropdown do not work

Question

I added custom fonts in my joditeditor component in react but custom fonts does not display the font preview in dropdown

useEffect(() => {
        const configSettings = {
            controls: {
                font: {
                    list: {
                        'Alegreya, serif': 'Alegreya',
                        'Alegreya Sans,sans-serif': 'Alegreya Sans',
                        'Alegreya Sans SC,sans-serif': 'Alegreya Sans SC',
                        'Alegreya SC,serif': 'Alegreya SC',
                        'Aleo,serif': 'Aleo',
                        'Assistant,sans-serif': 'Assistant',
                        'Barlow,sans-serif': 'Barlow',
                        'Barlow Condensed,sans-serif': 'Barlow Condensed',
                        'Barlow Semi Condensed,sans-serif': 'Barlow Semi Condensed',
                        'Bitter,serif': 'Bitter',
                        'Caladea,serif': 'Caladea',
                        'Dosis,sans-serif': 'Dosis',                      
                    },

font preview

i tried adding preview: true but still problem exist

                        'Roboto Slab,serif': 'Roboto Slab',
                        "'Slabo 13px',serif": 'Slabo 13px',
                        "'Slabo 27px',serif": 'Slabo 27px',
                        'Titillium Web,sans-serif': 'Titillium Web'
                    },
                    preview: true,