About utilities api customize

[ashikelasker]

first I import
@import "./node_modules/bootstrap/scss/functions";
@import "./node_modules/bootstrap/scss/variables";
@import "./node_modules/bootstrap/scss/utilities";

$utilities: (
"opacity": (
property: asdf,
values: (
0: 0,
25: 0.25,
50: 0.5,
75: 0.75,
90: 0.9,
100: 1,
),
),
);
@import "./node_modules/bootstrap/scss/bootstrap.scss";

then give me this error

Error: Undefined variable.
╷
164 │ values: $utilities-border-colors
│ ^^^^^^^^^^^^^^^^^^^^^^^^
╵
node_modules\bootstrap\scss_utilities.scss 164:15 @import
style.scss 3:9 root stylesheet

how can I solved it.....?