Custom Font Issues

[numan1889]

font-family:var(--typeBasePrimary),var(--typeBaseFallback);

when i comment this code , CLS remove and very low which i actual need , but whin i comment this fallback css code my whole site font-family change which is not needed and good for me . when webpage open css font family repeat its create CLS for my site . give me solution how can i handle it . and set also my needed or required font-family .