"An access date for an online work should...be provided if the work lacks a publication date" or if the work is likely to be revised or deleted (MLA Handbook, 9th ed., p. 211).
URLs
Author's Last name, First name. "Title of Document or Page." Name of Website, Publication Date, URL.
Galewitz, Phil. "In Depressed Rural Kentucky, Worries Mount Over Medicaid Cutbacks." NPR, 19 Nov. 2016, www.npr.org/sections/health-shots/2016/11/19/202580120/in-depressed-rural-kentucky-worries-mount-over-medicaid-cutbacks.
In-Text
Parenthetical: (Galewitz)
Narrative: Galewitz
"When a source has no page numbers... no number should be given in a parenthetical citation" (MLA Handbook, 9th ed., p. 248).
A narrative citation requires that you mention the the element that comes first for the relevant work in your list of works cited - e.g., the author's name/title, but nothing else is required.
Name of Organization. "Title of Document or Page." Name of Website, Publication Date, URL.
Mental Health Commission of Canada. "Mental Health Check-in: Helping Yourself and Others After Experiencing a Traumatic Event; Building a Self-Care Plan." 2019, https://bridgingthegap.mentalhealthcommission.ca/English/document/60986/helping-yourself-and-others-after-experiencing-traumatic-event-building-self-care-plan.
In-Text
Parenthetical: (Mental Health Commission of Canada)
Narrative: Mental Health Commission of Canada
The Name of Website element can be omitted if it is the same as the name of the organization (MLA Handbook, 9th ed., p.108).
"Title of Web Article." Name of Website, date, URL.
"Understanding Writing Assignments." OWL Purdue Online Writing Lab, 2021, owl.english.purdue.edu/owl/resource/544/01/.
In-Text
Parenthetical: ("Understanding Writing")
Narrative: "Understanding Writing"
In your list of works cited: "when a work is published without an author's name, do not list the author as "Anonymous." Instead, skip the author element and begin the entry with the work's title." (MLA Handbook, 9th ed., p. 108).
When citing such sources in-text, either cite the title in your prose or in parentheses. Note, "for concision, when a title is needed in a parenthetical citation, shorten the title if it is longer than a noun phrase" (MLA Handbook, 9th ed., p. 237).
"Title of Entry." Wikipedia, Date last modified, URL. Date Accessed.
"Donna Strickland." Wikipedia, 9 Oct. 2021, https://en.wikipedia.org/wiki/Donna_Strickland. Accessed 18 Oct. 2021.
In-Text
Parenthetical: ("Donna Strickland")
Narrative: "Donna Strickland"
See the Access Dates box above: Since Wikipedia articles are subject to frequent revision and may also be deleted without notice, the access date is included in this citation.
The date last modified is at the bottom of every Wikipedia page.
Author's Last Name, First Name or Username if real name not given. "Title of Post." Name of Platform, Publication Date, URL.
@persiankiwi. "We have report of large street battles in east & west of Tehran now - #Iranelection." X (formerly known as Twitter), 23 June 2009, 11:15 a.m., twitter.com/persiankiwi/status/2298106072.
In-Text
(@persiankiwi)
“Include pseudonyms, stage names, online usernames, and the like in the Author element, especially if the person is well known by that form of the name” (MLA Handbook, 9th ed., p. 107).
"Very long titles can be shortened in the list of works cited. Be sure to include enough of the title to make identification of the work unambiguous, and use ellipses to indicate that a title has been shortened" (MLA Handbook, 9th ed., p. 130).
Gaiman, Neil [@neilhimself]. "Crediting the publisher and not the artist contributes to the fiction that these comics were created by companies and not by people, and that nobody drew the original images." X (formerly known as Twitter), 13 November 2021, 8:23 a.m., https://twitter.com/neilhimself/status/1459557490757185536.
In-Text
(Gaiman)
“If an author's handle differs from the author's account name, it may be helpful to supply the handle in square brackets after the name...when the handle and account name are similar [...], you can usually omit the handle if you include the URL in your entry” MLA Handbook, 9th ed., p. 118).