As someone requested on FB group.
It contains the attached elementor container template and below css code that needs to be load before the container so you need to add it in the Customizer > Additional CSS or Child theme > style.css.

The curved container is made with svg image background, there is no other way around, so if you’re not confortable with this don’t use it.

/* Curved mobile bottom menu */
.bottom-nav {display:flex;justify-content:center;flex-direction:row;width:100%;height:50px;filter:drop-shadow(0 0 3px rgba(31, 31, 31, 0.5));position:fixed;bottom:0;}
.nav-slot {text-align:center;height:100%;display:flex;align-items:center;justify-content:center;}
.floating-button {position:fixed;width:50px;height:50px;line-height:3;text-align:center;color:#ffce54;border-radius:50%;bottom:35px;background-image:linear-gradient(to right, #6a11cb 0%, #2575fc 100%);box-shadow:0 10px 6px -6px #777;z-index:1;transition:0.3s all;}
.curve {flex-basis:auto !important;background-image: url(“data:image/svg+xml,%3Csvg xmlns=’http://www.w3.org/2000/svg’ fill=’%23fff’%3E%3Cpath d=’M99,0A36.33,36.33,0,0,0,70,15,25,25,0,0,1,30,15,36.33,36.33,0,0,0,1,0H0V50H100V0Z’/%3E%3C/svg%3E”);background-repeat:no-repeat;background-size:cover;background-position-y:center;width:100px;}

Note:
As is offered for free has not been intensively tested but looks to work well on different mobile browsers.
No support provided.