GTM blocking site rendering 1380 ms

hi i am experiencing some slow loading spetially in product pages. after checking with pagespeed inshights it tells me something blocking rendering crucial time:
/gtag/js?id=UA-88438540-1(www.googletagmanager.com). 39,0 KiB. 1380 ms

how can i fix the rendering blocking time? tank you

for example this product page https://www.ponponi.co.il/product/bambirainbow/

The page I need help with: [log in to see the link]