I am not able to replace text in my WordPress site

Hello dear concern I am running a website AiouStudio9.com where i need to place a text

[button color=”blue” size=”medium” link=”https://scontent.flhe14-1.fna.fbcdn.net/v/t1.6435-9/s720x720/187214704_1361905867523905_6626223705527189702_n.jpg?_nc_cat=100&_nc_map=control&ccb=1-3&_nc_sid=730e14&_nc_eui2=AeGf-qLRJQB289y7vdbj3J8K8mEyWSJyNj_yYTJZInI2P_tL1zrG3JieiC3CmSj3Dx8oHdYm7sl6W0cijVqcAes5&_nc_ohc=kN2ixptqB8oAX8wUs9p&_nc_ht=scontent.flhe14-1.fna&tp=7&oh=8c45c338bc1598494de8903ffa8fe900&oe=60CA2D75″ icon=”” target=”true”]Assignments Submit Form[/button]

with

[sc name=”aiouassignmentssubmitform”]

but when i search for this text it return no result on my site but when i search for a normal text which has no [] i am getting search hits i don’t know what is the reason please guide me through

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