I want to create design something like this

[snow whale]

How can I create this kind of design in react and what this design called ?

[desert sapphire]

Maybe in a grid with border radius and different widths?

[snow whale]

That can be done defining each image width and height
But if I fetch image from api then how Am I supposed to do ?

[desert sapphire]

You first fetch from the api then .map in the data with a return of img so it will render all images in the map, though I am still a bit confused in using .map

[stable trench]

hmm I don't think this design can be done using grid very easily. 🤔
I would probably use a canvas to achieve this.
p5js has an example for circles without overlapping:
https://editor.p5js.org/slow_izzm/sketches/HyqLs-7AX

You could tweak that code and render the images as your circle's background instead of a color.