whats wrong with following, there is no scrollbar in modal.why?

html part
<div id="myModal" class="modalappr">


    <div class="modal-contentappr shadow overflow-hidden" style="border-radius: 15px;">
        <div class="closeModalContainer d-flex justify-content-end">
            <button class="p-1 bg-whitesmoke border-0" id="closeModalBtn">

            <svg class="close-modal-btn" xmlns="http://www.w3.org/2000/svg" height="24px" viewBox="0 -960 960 960" width="24px" fill="#5f6368"><path d="m256-200-56-56 224-224-224-224 56-56 224 224 224-224 56 56-224 224 224 224-56 56-224-224-224 224Z" /></svg>
            </button>
        </div>
        

        <div id="modal-content-appr" class="d-flex justify-content-center" style="overflow-y: auto; max-height: 95%;">
            @* <form action="/" method="post"> *@
            @*     <input type="text" name="nextyear" value="" /> *@
            @* </form> *@

            <div class="m-0 form-container w-50 d-flex justify-content-start  flex-column">

                <h4 class=" h4 text-center my-2">
                    Heading</h4>
                    <form action="" class="m-2 ">

                        <div class="card p-0 px-4 m-0 align-items-center flex-column">

                            <div style="min-width: 250px;" class="w-50">

                                <div class="d-flex my-2 my-sm-3 my-lg-4 fs-7 row m-0">
                                    <label class="col-auto px-0 lightText" for="next_year_input">अग्रिम तिथि</label>
                                    <input name="next_year_input" type="date" id="caseCategoryInput" class="ms-3 p-2 border rounded  col me-0 bg-whitesmoke bg-whiteonfocus" required>
                                </div>


                                <div class="row m-0  d-flex flex-column justify-content-start align-items-start my-2 my-sm-3 my-lg-4 fs-7">
                                    <label for="remark_input" class=" col-12 col-sm-auto col-md-auto  text-sm-center p-0 lightText"> टिप्पणी  </label>
                                    <div class="descriptionbox col p-0">

                                        <textarea name="remark_input" id="remark_input" class="p-2 border rounded   w-100  bg-whitesmoke bg-whiteonfocus" rows="3"></textarea>
                                    </div>
                                </div>
                            </div>
                        </div>
                        <div class="button-section col-12    d-flex justify-content-center align-items-center my-2 my-sm-3 my-lg-4">
                            <!-- <input type="button" value="Add"> -->
                            <button type="submit" class="btn btn-primary p-2 px-4 mx-2 fs-7">Update</button>

                        </div>
                    </form>

            </div>

        </div>
    </div>

</div>

css part
.modalappr {
    display: none;
    position: fixed; /* Stay in place */
    z-index: 1; /* Sit on top */
    padding-top: 100px; /* Location of the box */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgb(0,0,0); /* Fallback color */
    background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
}


/* Modal Content */
.modal-contentappr {
    background-color: #fefefe;
    margin: auto;
    /* padding: 20px; */
    border: 1px solid #888;
    border-radius: 4px;
    width: 50%;
    min-width: 400px;
    /* height: 90%; */
    max-height: 90%;
    /* overflow-y: auto; */
}

.close-modal-btn {
    /* float: right; */
    /* margin: -17px; */
    padding: 0;
    cursor: pointer;
}

.fs-7 {
    font-size: 0.9rem;
}

.form-container {
    min-width: 400px;
}

.bg-whitesmoke {
    background-color: whitesmoke;
}

.bg-whiteonfocus:focus {
    background-color: white;
    ;
}

.lightText {
    color: rgb(100,100,100);
}

#closeModalBtn:hover{
    background-color: rgb(200,200,200);
}