How can i create vector strokes from image above in affinity designer or affinity photo i don't have Photoshop
There's no automatic bitmap tracing in Affinity. I has been under construction at least half an year. Maybe next summer? No schedules are available. Before it you must draw it manually.
Get Inkscape. It's free. The orange version took about 10 seconds to do.
Corner smoothing is disabled. There are path nodes only in corners and edge midpoints. White background is replaced by transparency.
See also a zoomed view without nodes:
To test it in Affinity Designer, some random edits are applied: