MP hi, in your Formula field you would Need to enter here 

Kruna wow, that's something big i didn't know yet ;) thanks!

still, is it also possible to add the code to a html function?

this is the code where i would like to implement a custom button within a grid container:

let term := (select Termine
        where 'Status (Angefragt - Zugesagt - Jederzeit - Erledigt)' = 2 or
        'Status (Angefragt - Zugesagt - Jederzeit - Erledigt)' = 3);
let zeit := (select Zeiterfassung);

let css := "
<style>
.grid-container {
    display:grid;
    grid-template-columns:repeat(auto-fill, minmax(20em, 1fr));
    grid-gap:20px;
}
.gridFormat{
    font-size:small;
    text-align:left;
    border-radius:.5em;
    padding:1em;
    color:white;
}
span:hover{
    cursor:pointer;
}

.gridOne {background-color:#5834b9;}
</style>

";
let content := ---
<aside class = 'grid-container'>{ for aa in term do }

<aside class =  'gridFormat gridOne'>

    <span onclick="ui.popupRecord('{ aa }')">
    <b>{ aa.KD }
   <span style="
    border-radius: .5em;
    background-color: red;
    ">{ aa.plc }</span>


   // Here i would like to implement the custom button


    </b></aside>{ end }
</aside>
    ---;
html(head + css + content)

MP I am Not sure, if I understood right, but try this instead

<button onclick="ui.popupRecord('{ aa }')">
    <b>{ aa.KD }
   <span style="
    border-radius: .5em;
    background-color: red;
    ">{ aa.plc }</button>

Kruna the code works fine, but i would like to implement the custom button here ;)

When entering the code into a formular field, it produces a flex grid box for each due appointment in my "appointment" table. when i click on the box, it opens the appointment. now i would like to have several custom buttons within the box:

MP can you pls upload a dummy sample database to look into it?

would be easier for me to help :-)

Kruna i've found a solution, even though it might not be the most elegant one ;)

as i don't want to continue spamming this post, i've started a new topic:

https://forum.ninox.com/t/x2y6gb7 with a dummy-DB of my project ;)