Compile error, works fine in ionic serve though. how to turn off error checking?

Ionic Framework
1 
      input3.firstChild.select();
                              ~~~~~~
src/app/monitorinputmulti2/monitorinputmulti2.page.ts:205:27 - error TS2339: Property 'select' does not exist on type 'ChildNode'.

yes at compile time theres no child , but later in the actual code there will be one and it works fine

how can i turn off the error checking on compile?