wx.showKeyboard is not a function

The error message "wx.showKeyboard is not a function" is usually caused by a couple of reasons.

First, make sure that you are using the correct syntax for the function. The correct syntax for the showKeyboard function is:

wx.showKeyboard({
  defaultValue: '',
  maxLength: 50,
  multiple: false,
  confirmHold: true,
  confirmType: 'done',
  success: function (res) {
    console.log(res.value)
  },
  fail: function (res) {
    console.log(res.errMsg)
  }
})

Second, make sure that you have included the necessary libraries or modules in your code. If the showKeyboard function is not included in your code, you will need to import it or add it to your project.

Lastly, check if the version of WeChat Mini Program you are using supports the showKeyboard function. If not, you may need to update your WeChat Mini Program version to the latest one that supports this function.